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• Windows Azure Myths

  - by BuckWoody

  Windows Azure is part of the Microsoft "stack" - the suite of software and services we offer. Because we have so many products in almost every part of technology, it's hard to know everything about all parts of what we do - even for those of us who work here. So it's no surprise that some folks are not as familiar with Windows and SQL Azure as they are, say Windows Server or XBox. As I chat with folks about a solution for a business or organization need, I put Windows Azure into the mix. I always start off with "What do you already know about Windows Azure?" so that I don't bore folks with information they already have. I some cases they've checked out the product ahead of time and have specific questions, in others they aren't as familiar, and in still others there is a fair amount of mis-information. Sometimes that's because of a marketing failure, sometimes it's hearsay, and somtetimes it's active misinformation. I thought I might lay out a few of these misconceptions. As always - do your fact-checking! Never take anyone's word alone (including mine) as gospel. Make sure you educate yourself on your options. Your company or your clients depend on you to have the right information on IT, so make sure you live up to that. Myth 1: Nobody uses Windows Azure It's true that we don't give out numbers on the amount of clients on Windows and SQL Azure. But lots of folks are here - companies you may have heard of like Boeing, NASA, Fujitsu, The City of London, Nuedesic, and many others. I deal with firms small and large that use Windows Azure for mission-critical applications, sometimes totally on Windows and/or SQL Azure, sometimes in conjunction with an on-premises system, sometimes for only a specific component in Windows Azure like storage. The interesting thing is that many sites you visit have a Windows Azure component, or are running on Windows Azure. They just don't announce it. Just like the other cloud providers, the companies have asked to be completely branded themselves - they don't want you to be aware or care that they are on Windows Azure. Sometimes that's for security, other times it's for different reasons. It's just like the web sites you visit. For the most part, they don't advertise which OS or Web Server they use. It really just shouldn't matter. The point is that they just use what works to solve a given problem. Check out a few public case studies here: https://www.windowsazure.com/en-us/home/case-studies/ Myth 2: It's only for Microsoft stuff - can't use Open Source This is the one I face the most, and am the most dismayed by. We work just fine with many open source products, including Java, NodeJS, PHP, Ruby, Python, Hadoop, and many other languages and applications. You can quickly deploy a Wordpress, Umbraco and other "kits". We have software development kits (SDK's) for iPhones, iPads, Android, Windows phones and more. We have an SDK to work with FaceBook and other social networks. In short, we play well with others. More on the languages and runtimes we support here: https://www.windowsazure.com/en-us/develop/overview/ More on the SDK's here: http://www.wadewegner.com/2011/05/windows-azure-toolkit-for-ios/, http://www.wadewegner.com/2011/08/windows-azure-toolkits-for-devices-now-with-android/, http://azuretoolkit.codeplex.com/ Myth 3: Microsoft expects me to switch everything to "the cloud" No, we don't. That would be disasterous, unless the only things you run in your company uses works perfectly in Azure. Use Windows Azure  - or any cloud for that matter - where it works. Whenever I talk to companies, I focus on two things: Something that is broken and needs to be re-architected Something you want to do that is new If something is broken, and you need new tools to scale, extend, add capacity dynamically and so on, then you can consider using Windows or SQL Azure. It can help solve problems that you have, or it may include a component you don't want to write or architect yourself. Sometimes you want to do something new, like extend your company's offerings to mobile phones, to the web, or to a social network. More info on where it works here: http://blogs.msdn.com/b/buckwoody/archive/2011/01/18/windows-azure-and-sql-azure-use-cases.aspx Myth 4: I have to write code to use Windows and SQL Azure If Windows Azure is a PaaS - a Platform as a Service - then don't you have to write code to use it? Nope. Windows and SQL Azure are made up of various components. Some of those components allow you to write and deploy code (like Compute) and others don't. We have lots of customers using Windows Azure storage as a backup, to securely share files instead of using DropBox, to distribute videos or code or firmware, and more. Others use our High Performance Computing (HPC) offering to rent a supercomputer when they need one. You can even throw workloads at that using Excel! In addition there are lots of other components in Windows Azure you can use, from the Windows Azure Media Services to others. More here: https://www.windowsazure.com/en-us/home/scenarios/saas/ Myth 5: Windows Azure is just another form of "vendor lock-in" Windows Azure uses .NET, OSS languages and standard interfaces for the code. Sure, you're not going to take the code line-for-line and run it on a mainframe, but it's standard code that you write, and can port to something else. And the data is yours - you can bring it back whever you want. It's either in text or binary form, that you have complete control over. There are no licenses - you can "pay as you go", and when you're done, you can leave the service and take all your code, data and IP with you.   So go out there, read up, try it. Use it where it works. And don't believe everything you hear - sometimes the Internet doesn't get it all correct. :)

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• Does Test Driven Development (TDD) improve Quality and Correctness? (Part 1)

  - by David V. Corbin

  Since the dawn of the computer age, various methodologies have been introduced to improve quality and reduce cost. In this posting, I will by sharing my experiences with Test Driven Development; both its benefits and limitations. To start this topic, we need to agree on what TDD is. The first is to define each of the three words as used in this context. Test - An item or action which measures something in some quantifiable form. Driven - The primary motivation or focus of a series of activities (process) Development - All phases of a software project/product from concept through delivery. The above are very simple definitions that result in the following: "TDD is a process where the primary focus is on measuring and quantifying all aspects of the creation of a (software) product." There are many places where TDD is used outside of software development, even though it is not known by this name. Consider the (conventional) education process that most of us grew up on. The focus was to get the best grades as measured by different tests. Many of these tests measured rote memorization and not understanding of the subject matter. The result of this that many people graduated with high scores but without "quality and correctness" in their ability to utilize the subject matter (of course, the flip side is true where certain people DID understand the material but were not very good at taking this type of test). Returning to software development, let us look at some common scenarios. While these items are generally applicable regardless of platform, language and tools; the remainder of this post will utilize Microsoft Visual Studio and Team Foundation Server (TFS) for examples. It should be realized that everyone does at least some aspect of TDD. At the most rudimentary level, getting a program to compile involves a "pass/fail" measurement (is the syntax valid) that drives their ability to proceed further (run the program). Other developers may create "Unit Tests" in the belief that having a test for every method/property of a class and good code coverage is the goal of TDD. These items may be helpful and even important, but really only address a small aspect of the overall effort. To see TDD in a bigger view, lets identify the various activities that are part of the Software Development LifeCycle. These are going to be presented in a Waterfall style for simplicity, but each item also occurs within Iterative methodologies such as Agile/Scrum. the key ones here are: Requirements Gathering Architecture Design Implementation Quality Assurance Can each of these items be subjected to a process which establishes metrics (quantified metrics) that reflect both the quality and correctness of each item? It should be clear that conventional Unit Tests do not apply to all of these items; at best they can verify that a local aspect (e.g. a Class/Method) of implementation matches the (test writers perspective of) the appropriate design document. So what can we do? For each of area, the goal is to create tests that are quantifiable and durable. The ability to quantify the measurements (beyond a simple pass/fail) is critical to tracking progress(eventually measuring the level of success that has been achieved) and for providing clear information on what items need to be addressed (along with the appropriate time to address them - in varying levels of detail) . Durability is important so that the test can be reapplied (ideally in an automated fashion) over the entire cycle. Returning for a moment back to our "education example", one must also be careful of how the tests are organized and how the measurements are taken. If a test is in a multiple choice format, there is a significant statistical probability that a correct answer might be the result of a random guess. Also, in many situations, having the student simply provide a final answer can obscure many important elements. For example, on a math test, having the student simply provide a numeric answer (rather than showing the methodology) may result in a complete mismatch between the process and the result. It is hard to determine which is worse: The student who makes a simple arithmetric error at one step of a long process (resulting in a wrong answer) or The student who (without providing the "workflow") uses a completely invalid approach, yet still comes up with the right number. The "Wrong Process"/"Right Answer" is probably the single biggest problem in software development. Even very simple items can suffer from this. As an example consider the following code for a "straight line" calculation....Is it correct? (for Integral Points)         int Solve(int m, int b, int x) { return m * x + b; }   Most people would respond "Yes". But let's take the question one step further... Is it correct for all possible values of m,b,x??? (no fair if you cheated by being focused on the bolded text!)  Without additional information regarding constrains on "the possible values of m,b,x" the answer must be NO, there is the risk of overflow/wraparound that will produce an incorrect result! To properly answer this question (i.e. Test the Code), one MUST be able to backtrack from the implementation through the design, and architecture all the way back to the requirements. And the requirement itself must be tested against the stakeholder(s). It is only when the bounding conditions are defined that it is possible to determine if the code is "Correct" and has "Quality". Yet, how many of us (myself included) have written such code without even thinking about it. In many canses we (think we) "know" what the bounds are, and that the code will be correct. As we all know, requirements change, "code reuse" causes implementations to be applied to different scenarios, etc. This leads directly to the types of system failures that plague so many projects. This approach to TDD is much more holistic than ones which start by focusing on the details. The fundamental concepts still apply: Each item should be tested. The test should be defined/implemented before (or concurrent with) the definition/implementation of the actual item. We also add concepts that expand the scope and alter the style by recognizing: There are many things beside "lines of code" that benefit from testing (measuring/evaluating in a formal way) Correctness and Quality can not be solely measured by "correct results" In the future parts, we will examine in greater detail some of the techniques that can be applied to each of these areas....

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• T-SQL Tuesday #31 - Logging Tricks with CONTEXT_INFO

  - by Most Valuable Yak (Rob Volk)

  This month's T-SQL Tuesday is being hosted by Aaron Nelson [b | t], fellow Atlantan (the city in Georgia, not the famous sunken city, or the resort in the Bahamas) and covers the topic of logging (the recording of information, not the harvesting of trees) and maintains the fine T-SQL Tuesday tradition begun by Adam Machanic [b | t] (the SQL Server guru, not the guy who fixes cars, check the spelling again, there will be a quiz later). This is a trick I learned from Fernando Guerrero [b | t] waaaaaay back during the PASS Summit 2004 in sunny, hurricane-infested Orlando, during his session on Secret SQL Server (not sure if that's the correct title, and I haven't used parentheses in this paragraph yet).  CONTEXT_INFO is a neat little feature that's existed since SQL Server 2000 and perhaps even earlier.  It lets you assign data to the current session/connection, and maintains that data until you disconnect or change it.  In addition to the CONTEXT_INFO() function, you can also query the context_info column in sys.dm_exec_sessions, or even sysprocesses if you're still running SQL Server 2000, if you need to see it for another session. While you're limited to 128 bytes, one big advantage that CONTEXT_INFO has is that it's independent of any transactions.  If you've ever logged to a table in a transaction and then lost messages when it rolled back, you can understand how aggravating it can be.  CONTEXT_INFO also survives across multiple SQL batches (GO separators) in the same connection, so for those of you who were going to suggest "just log to a table variable, they don't get rolled back":  HA-HA, I GOT YOU!  Since GO starts a new batch all variable declarations are lost. Here's a simple example I recently used at work.  I had to test database mirroring configurations for disaster recovery scenarios and measure the network throughput.  I also needed to log how long it took for the script to run and include the mirror settings for the database in question.  I decided to use AdventureWorks as my database model, and Adam Machanic's Big Adventure script to provide a fairly large workload that's repeatable and easily scalable.  My test would consist of several copies of AdventureWorks running the Big Adventure script while I mirrored the databases (or not). Since Adam's script contains several batches, I decided CONTEXT_INFO would have to be used.  As it turns out, I only needed to grab the start time at the beginning, I could get the rest of the data at the end of the process.   The code is pretty small: declare @time binary(128)=cast(getdate() as binary(8)) set context_info @time   ... rest of Big Adventure code ...   go use master; insert mirror_test(server,role,partner,db,state,safety,start,duration) select @@servername, mirroring_role_desc, mirroring_partner_instance, db_name(database_id), mirroring_state_desc, mirroring_safety_level_desc, cast(cast(context_info() as binary(8)) as datetime), datediff(s,cast(cast(context_info() as binary(8)) as datetime),getdate()) from sys.database_mirroring where db_name(database_id) like 'Adv%';   I declared @time as a binary(128) since CONTEXT_INFO is defined that way.  I couldn't convert GETDATE() to binary(128) as it would pad the first 120 bytes as 0x00.  To keep the CAST functions simple and avoid using SUBSTRING, I decided to CAST GETDATE() as binary(8) and let SQL Server do the implicit conversion.  It's not the safest way perhaps, but it works on my machine. :) As I mentioned earlier, you can query system views for sessions and get their CONTEXT_INFO.  With a little boilerplate code this can be used to monitor long-running procedures, in case you need to kill a process, or are just curious  how long certain parts take.  In this example, I added code to Adam's Big Adventure script to set CONTEXT_INFO messages at strategic places I want to monitor.  (His code is in UPPERCASE as it was in the original, mine is all lowercase): declare @msg binary(128) set @msg=cast('Altering bigProduct.ProductID' as binary(128)) set context_info @msg go ALTER TABLE bigProduct ALTER COLUMN ProductID INT NOT NULL GO set context_info 0x0 go declare @msg1 binary(128) set @msg1=cast('Adding pk_bigProduct Constraint' as binary(128)) set context_info @msg1 go ALTER TABLE bigProduct ADD CONSTRAINT pk_bigProduct PRIMARY KEY (ProductID) GO set context_info 0x0 go declare @msg2 binary(128) set @msg2=cast('Altering bigTransactionHistory.TransactionID' as binary(128)) set context_info @msg2 go ALTER TABLE bigTransactionHistory ALTER COLUMN TransactionID INT NOT NULL GO set context_info 0x0 go declare @msg3 binary(128) set @msg3=cast('Adding pk_bigTransactionHistory Constraint' as binary(128)) set context_info @msg3 go ALTER TABLE bigTransactionHistory ADD CONSTRAINT pk_bigTransactionHistory PRIMARY KEY NONCLUSTERED(TransactionID) GO set context_info 0x0 go declare @msg4 binary(128) set @msg4=cast('Creating IX_ProductId_TransactionDate Index' as binary(128)) set context_info @msg4 go CREATE NONCLUSTERED INDEX IX_ProductId_TransactionDate ON bigTransactionHistory(ProductId,TransactionDate) INCLUDE(Quantity,ActualCost) GO set context_info 0x0   This doesn't include the entire script, only those portions that altered a table or created an index.  One annoyance is that SET CONTEXT_INFO requires a literal or variable, you can't use an expression.  And since GO starts a new batch I need to declare a variable in each one.  And of course I have to use CAST because it won't implicitly convert varchar to binary.  And even though context_info is a nullable column, you can't SET CONTEXT_INFO NULL, so I have to use SET CONTEXT_INFO 0x0 to clear the message after the statement completes.  And if you're thinking of turning this into a UDF, you can't, although a stored procedure would work. So what does all this aggravation get you?  As the code runs, if I want to see which stage the session is at, I can run the following (assuming SPID 51 is the one I want): select CAST(context_info as varchar(128)) from sys.dm_exec_sessions where session_id=51   Since SQL Server 2005 introduced the new system and dynamic management views (DMVs) there's not as much need for tagging a session with these kinds of messages.  You can get the session start time and currently executing statement from them, and neatly presented if you use Adam's sp_whoisactive utility (and you absolutely should be using it).  Of course you can always use xp_cmdshell, a CLR function, or some other tricks to log information outside of a SQL transaction.  All the same, I've used this trick to monitor long-running reports at a previous job, and I still think CONTEXT_INFO is a great feature, especially if you're still using SQL Server 2000 or want to supplement your instrumentation.  If you'd like an exercise, consider adding the system time to the messages in the last example, and an automated job to query and parse it from the system tables.  That would let you track how long each statement ran without having to run Profiler. #TSQL2sDay

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• The Shift: how Orchard painlessly shifted to document storage, and how it’ll affect you

  - by Bertrand Le Roy

  We’ve known it all along. The storage for Orchard content items would be much more efficient using a document database than a relational one. Orchard content items are composed of parts that serialize naturally into infoset kinds of documents. Storing them as relational data like we’ve done so far was unnatural and requires the data for a single item to span multiple tables, related through 1-1 relationships. This means lots of joins in queries, and a great potential for Select N+1 problems. Document databases, unfortunately, are still a tough sell in many places that prefer the more familiar relational model. Being able to x-copy Orchard to hosters has also been a basic constraint in the design of Orchard. Combine those with the necessity at the time to run in medium trust, and with license compatibility issues, and you’ll find yourself with very few reasonable choices. So we went, a little reluctantly, for relational SQL stores, with the dream of one day transitioning to document storage. We have played for a while with the idea of building our own document storage on top of SQL databases, and Sébastien implemented something more than decent along those lines, but we had a better way all along that we didn’t notice until recently… In Orchard, there are fields, which are named properties that you can add dynamically to a content part. Because they are so dynamic, we have been storing them as XML into a column on the main content item table. This infoset storage and its associated API are fairly generic, but were only used for fields. The breakthrough was when Sébastien realized how this existing storage could give us the advantages of document storage with minimal changes, while continuing to use relational databases as the substrate. public bool CommercialPrices { get { return this.Retrieve(p => p.CommercialPrices); } set { this.Store(p => p.CommercialPrices, value); } } This code is very compact and efficient because the API can infer from the expression what the type and name of the property are. It is then able to do the proper conversions for you. For this code to work in a content part, there is no need for a record at all. This is particularly nice for site settings: one query on one table and you get everything you need. This shows how the existing infoset solves the data storage problem, but you still need to query. Well, for those properties that need to be filtered and sorted on, you can still use the current record-based relational system. This of course continues to work. We do however provide APIs that make it trivial to store into both record properties and the infoset storage in one operation: public double Price { get { return Retrieve(r => r.Price); } set { Store(r => r.Price, value); } } This code looks strikingly similar to the non-record case above. The difference is that it will manage both the infoset and the record-based storages. The call to the Store method will send the data in both places, keeping them in sync. The call to the Retrieve method does something even cooler: if the property you’re looking for exists in the infoset, it will return it, but if it doesn’t, it will automatically look into the record for it. And if that wasn’t cool enough, it will take that value from the record and store it into the infoset for the next time it’s required. This means that your data will start automagically migrating to infoset storage just by virtue of using the code above instead of the usual: public double Price { get { return Record.Price; } set { Record.Price = value; } } As your users browse the site, it will get faster and faster as Select N+1 issues will optimize themselves away. If you preferred, you could still have explicit migration code, but it really shouldn’t be necessary most of the time. If you do already have code using QueryHints to mitigate Select N+1 issues, you might want to reconsider those, as with the new system, you’ll want to avoid joins that you don’t need for filtering or sorting, further optimizing your queries. There are some rare cases where the storage of the property must be handled differently. Check out this string[] property on SearchSettingsPart for example: public string[] SearchedFields { get { return (Retrieve<string>("SearchedFields") ?? "") .Split(new[] {',', ' '}, StringSplitOptions.RemoveEmptyEntries); } set { Store("SearchedFields", String.Join(", ", value)); } } The array of strings is transformed by the property accessors into and from a comma-separated list stored in a string. The Retrieve and Store overloads used in this case are lower-level versions that explicitly specify the type and name of the attribute to retrieve or store. You may be wondering what this means for code or operations that look directly at the database tables instead of going through the new infoset APIs. Even if there is a record, the infoset version of the property will win if it exists, so it is necessary to keep the infoset up-to-date. It’s not very complicated, but definitely something to keep in mind. Here is what a product record looks like in Nwazet.Commerce for example: And here is the same data in the infoset: The infoset is stored in Orchard_Framework_ContentItemRecord or Orchard_Framework_ContentItemVersionRecord, depending on whether the content type is versionable or not. A good way to find what you’re looking for is to inspect the record table first, as it’s usually easier to read, and then get the item record of the same id. Here is the detailed XML document for this product: <Data> <ProductPart Inventory="40" Price="18" Sku="pi-camera-box" OutOfStockMessage="" AllowBackOrder="false" Weight="0.2" Size="" ShippingCost="null" IsDigital="false" /> <ProductAttributesPart Attributes="" /> <AutoroutePart DisplayAlias="camera-box" /> <TitlePart Title="Nwazet Pi Camera Box" /> <BodyPart Text="[...]" /> <CommonPart CreatedUtc="2013-09-10T00:39:00Z" PublishedUtc="2013-09-14T01:07:47Z" /> </Data> The data is neatly organized under each part. It is easy to see how that document is all you need to know about that content item, all in one table. If you want to modify that data directly in the database, you should be careful to do it in both the record table and the infoset in the content item record. In this configuration, the record is now nothing more than an index, and will only be used for sorting and filtering. Of course, it’s perfectly fine to mix record-backed properties and record-less properties on the same part. It really depends what you think must be sorted and filtered on. In turn, this potentially simplifies migrations considerably. So here it is, the great shift of Orchard to document storage, something that Orchard has been designed for all along, and that we were able to implement with a satisfying and surprising economy of resources. Expect this code to make its way into the 1.8 version of Orchard when that’s available.

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• Microsoft and the open source community

  - by Charles Young

  For the last decade, I have repeatedly, in my imitable Microsoft fan boy style, offered an alternative view to commonly held beliefs about Microsoft's stance on open source licensing.  In earlier times, leading figures in Microsoft were very vocal in resisting the idea that commercial licensing is outmoded or morally reprehensible.  Many people interpreted this as all-out corporate opposition to open source licensing.  I never read it that way. It is true that I've met individual employees of Microsoft who are antagonistic towards FOSS (free and open source software), but I've met more who are supportive or at least neutral on the subject.  In any case, individual attitudes of employees don't necessarily reflect a corporate stance.  The strongest opposition I've encountered has actually come from outside the company.  It's not a charitable thought, but I sometimes wonder if there are people in the .NET community who are opposed to FOSS simply because they believe, erroneously, that Microsoft is opposed. Here, for what it is worth, are the points I've repeated endlessly over the years and which have often been received with quizzical scepticism. a)  A decade ago, Microsoft's big problem was not FOSS per se, or even with copyleft.  The thing which really kept them awake at night was the fear that one day, someone might find, deep in the heart of the Windows code base, some code that should not be there and which was published under GPL.  The likelihood of this ever happening has long since faded away, but there was a time when MS was running scared.  I suspect this is why they held out for a while from making Windows source code open to inspection.  Nowadays, as an MVP, I am positively encouraged to ask to see Windows source. b)  Microsoft has never opposed the open source community.  They have had problems with specific people and organisations in the FOSS community.  Back in the 1990s, Richard Stallman gave time and energy to a successful campaign to launch antitrust proceedings against Microsoft.  In more recent times, the negative attitude of certain people to Microsoft's submission of two FOSS licences to the OSI (both of which have long since been accepted), and the mad scramble to try to find any argument, however tenuous, to block their submission was not, let us say, edifying. c) Microsoft has never, to my knowledge, written off the FOSS model.  They certainly don't agree that more traditional forms of licensing are inappropriate or immoral, and they've always been prepared to say so.  One reason why it was so hard to convince people that Microsoft is not rabidly antagonistic towards FOSS licensing is that so many people think they have no involvement in open source.  A decade ago, there was virtually no evidence of any such involvement.  However, that was a long time ago.  Quietly over the years, Microsoft has got on with the job of working out how to make use of FOSS licensing and how to support the FOSS community.  For example, as well as making increasingly extensive use of Github, they run an important FOSS forge (CodePlex) on which they, themselves, host many hundreds of distinct projects.  The total count may even be in the thousands now.  I suspect there is a limit of about 500 records on CodePlex searches because, for the past few years, whenever I search for Microsoft-specific projects on CodePlex, I always get approx. 500 hits.  Admittedly, a large volume of the stuff they publish under FOSS licences amounts to code samples, but many of those 'samples' have grown into useful and fully featured frameworks, libraries and tools. All this is leading up to the observation that yesterday's announcement by Scott Guthrie marks a significant milestone and should not go unnoticed.  If you missed it, let me summarise.   From the first release of .NET, Microsoft has offered a web development framework called ASP.NET.  The core libraries are included in the .NET framework which is released free of charge, but which is not open source.   However, in recent years, the number of libraries that constitute ASP.NET have grown considerably.  Today, most professional ASP.NET web development exploits the ASP.NET MVC framework.  This, together with several other important parts of the ASP.NET technology stack, is released on CodePlex under the Apache 2.0 licence.   Hence, today, a huge swathe of web development on the .NET/Azure platform relies four-square on the use of FOSS frameworks and libraries. Yesterday, Scott Guthrie announced the next stage of ASP.NET's journey towards FOSS nirvana.  This involves extending ASP.NET's FOSS stack to include Web API and the MVC Razor view engine which is rapidly becoming the de facto 'standard' for building web pages in ASP.NET.  However, perhaps the more important announcement is that the ASP.NET team will now accept and review contributions from the community.  Scott points out that this model is already in place elsewhere in Microsoft, and specifically draws attention to development of the Windows Azure SDKs.  These SDKs are central to Azure development.   The .NET and Java SDKs are published under Apache 2.0 on Github and Microsoft is open to community contributions.  Accepting contributions is a more profound move than simply releasing code under FOSS licensing.  It means that Microsoft is wholeheartedly moving towards a full-blooded open source approach for future evolution of some of their central and most widely used .NET and Azure frameworks and libraries.  In conjunction with Scott's announcement, Microsoft has also released Git support for CodePlex (at long last!) and, perhaps more importantly, announced significant new investment in their own FOSS forge. Here at Solidsoft we have several reasons to be very interested in Scott's announcement. I'll draw attention to one of them.  Earlier this year we wrote the initial version of a new UK Government web application called CloudStore.  CloudStore provides a way for local and central government to discover and purchase applications and services. We wrote the web site using ASP.NET MVC which is FOSS.  However, this point has been lost on the ladies and gentlemen of the press and, I suspect, on some of the decision makers on the government side.  They announced a few weeks ago that future versions of CloudStore will move to a FOSS framework, clearly oblivious of the fact that it is already built on a FOSS framework.  We are, it is fair to say, mildly irked by the uninformed and badly out-of-date assumption that “if it is Microsoft, it can't be FOSS”.  Old prejudices live on.

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• CodePlex Daily Summary for Tuesday, November 22, 2011

  CodePlex Daily Summary for Tuesday, November 22, 2011Popular ReleasesDeveloper Team Article System Management: DTASM v1.3: ?? ??? ???? 3 ????? ???? ???? ????? ??? : - ????? ?????? ????? ???? ?? ??? ???? ????? ?? ??? ? ?? ???? ?????? ???? ?? ???? ????? ?? . - ??? ?? ???? ????? ???? ????? ???? ???? ?? ????? , ?????? ????? ????? ?? ??? . - ??? ??????? ??? ??? ???? ?? ????? ????? ????? .VideoLan DotNet for WinForm, WPF & Silverlight 5: VideoLan DotNet for WinForm, WPF, SL5 - 2011.11.22: The new version contains Silverlight 5 library: Vlc.DotNet.Silverlight. A sample could be tested here The new version add and correct many features : Correction : Reinitialize some variables Deprecate : Logging API, since VLC 1.2 (08/20/2011) Add subitem in LocationMedia (for Youtube videos, ...) Update Wpf sample to use Youtube videos Many others correctionsSharePoint 2010 FBA Pack: SharePoint 2010 FBA Pack 1.2.0: Web parts are now fully customizable via html templates (Issue #323) FBA Pack is now completely localizable using resource files. Thank you David Chen for submitting the code as well as Chinese translations of the FBA Pack! The membership request web part now gives the option of having the user enter the password and removing the captcha (Issue # 447) The FBA Pack will now work in a zone that does not have FBA enabled (Another zone must have FBA enabled, and the zone must contain the me...SharePoint 2010 Education Demo Project: Release SharePoint SP1 for Education Solutions: This release includes updates to the Content Packs for SharePoint SP1. All Content Packs have been updated to install successfully under SharePoint SP1SQL Monitor - tracking sql server activities: SQLMon 4.1 alpha 6: 1. improved support for schema 2. added find reference when right click on object list 3. added object rename supportBugNET Issue Tracker: BugNET 0.9.126: First stable release of version 0.9. Upgrades from 0.8 are fully supported and upgrades to future releases will also be supported. This release is now compiled against the .NET 4.0 framework and is a requirement. Because of this the web.config has significantly changed. After upgrading, you will need to configure the authentication settings for user registration and anonymous access again. Please see our installation / upgrade instructions for more details: http://wiki.bugnetproject.c...Anno 2070 Assistant: v0.1.0 (STABLE): Version 0.1.0 Features Production Chains Eco Production Chains (Complete) Tycoon Production Chains (Disabled - Incomplete) Tech Production Chains (Disabled - Incomplete) Supply (Disabled - Incomplete) Calculator (Disabled - Incomplete) Building Layouts Eco Building Layouts (Complete) Tycoon Building Layouts (Disabled - Incomplete) Tech Building Layouts (Disabled - Incomplete) Credits (Complete)Free SharePoint 2010 Sites Templates: SharePoint Server 2010 Sites Templates: here is the list of sites templates to be downloadedVsTortoise - a TortoiseSVN add-in for Microsoft Visual Studio: VsTortoise Build 30 Beta: Note: This release does not work with custom VsTortoise toolbars. These get removed every time when you shutdown Visual Studio. (#7940) Build 30 (beta)New: Support for TortoiseSVN 1.7 added. (the download contains both setups, for TortoiseSVN 1.6 and 1.7) New: OpenModifiedDocumentDialog displays conflicted files now. New: OpenModifiedDocument allows to group items by changelist now. Fix: OpenModifiedDocumentDialog caused Visual Studio 2010 to freeze sometimes. Fix: The installer didn...nopCommerce. Open source shopping cart (ASP.NET MVC): nopcommerce 2.30: Highlight features & improvements: • Performance optimization. • Back in stock notifications. • Product special price support. • Catalog mode (based on customer role) To see the full list of fixes and changes please visit the release notes page (http://www.nopCommerce.com/releasenotes.aspx).WPF Converters: WPF Converters V1.2.0.0: support for enumerations, value types, and reference types in the expression converter's equality operators the expression converter now handles DependencyProperty.UnsetValue as argument values correctly (#4062) StyleCop conformance (more or less)Json.NET: Json.NET 4.0 Release 4: Change - JsonTextReader.Culture is now CultureInfo.InvariantCulture by default Change - KeyValurPairConverter no longer cares about the order of the key and value properties Change - Time zone conversions now use new TimeZoneInfo instead of TimeZone Fix - Fixed boolean values sometimes being capitalized when converting to XML Fix - Fixed error when deserializing ConcurrentDictionary Fix - Fixed serializing some Uris returning the incorrect value Fix - Fixed occasional error when...Media Companion: MC 3.423b Weekly: Ensure .NET 4.0 Full Framework is installed. (Available from http://www.microsoft.com/download/en/details.aspx?id=17718) Ensure the NFO ID fix is applied when transitioning from versions prior to 3.416b. (Details here) Replaced 'Rebuild' with 'Refresh' throughout entire code. Rebuild will now be known as Refresh. mc_com.exe has been fully updated TV Show Resolutions... Resolved issue #206 - having to hit save twice when updating runtime manually Shrunk cache size and lowered loading times f...Delta Engine: Delta Engine Beta Preview v0.9.1: v0.9.1 beta release with lots of refactoring, fixes, new samples and support for iOS, Android and WP7 (you need a Marketplace account however). If you want a binary release for the games (like v0.9.0), just say so in the Forum or here and we will quickly prepare one. It is just not much different from v0.9.0, so I left it out this time. See http://DeltaEngine.net/Wiki.Roadmap for details.SharpMap - Geospatial Application Framework for the CLR: SharpMap-0.9-AnyCPU-Trunk-2011.11.17: This is a build of SharpMap from the 0.9 development trunk as per 2011-11-17 For most applications the AnyCPU release is the recommended, but in case you need an x86 build that is included to. For some dataproviders (GDAL/OGR, SqLite, PostGis) you need to also referense the SharpMap.Extensions assembly For SqlServer Spatial you need to reference the SharpMap.SqlServerSpatial assemblyAJAX Control Toolkit: November 2011 Release: AJAX Control Toolkit Release Notes - November 2011 Release Version 51116November 2011 release of the AJAX Control Toolkit. AJAX Control Toolkit .NET 4 - Binary – AJAX Control Toolkit for .NET 4 and sample site (Recommended). AJAX Control Toolkit .NET 3.5 - Binary – AJAX Control Toolkit for .NET 3.5 and sample site (Recommended). Notes: - The current version of the AJAX Control Toolkit is not compatible with ASP.NET 2.0. The latest version that is compatible with ASP.NET 2.0 can be found h...Microsoft Ajax Minifier: Microsoft Ajax Minifier 4.36: Fix for issue #16908: string literals containing ASP.NET replacement syntax fail if the ASP.NET code contains the same character as the string literal delimiter. Also, we shouldn't be changing the delimiter for those literals or combining them with other literals; the developer may have specifically chosen the delimiter used because of possible content inserted by ASP.NET code. This logic is normally off; turn it on via the -aspnet command-line flag (or the Code.Settings.AllowEmbeddedAspNetBl...MVC Controls Toolkit: Mvc Controls Toolkit 1.5.5: Added: Now the DateRanteAttribute accepts complex expressions containing "Now" and "Today" as static minimum and maximum. Menu, MenuFor helpers capable of handling a "currently selected element". The developer can choose between using a standard nested menu based on a standard SimpleMenuItem class or specifying an item template based on a custom class. Added also helpers to build the tree structure containing all data items the menu takes infos from. Improved the pager. Now the developer ...SharpCompress - a fully native C# library for RAR, 7Zip, Zip, Tar, GZip, BZip2: SharpCompress 0.7: Reworked API to be more consistent. See Supported formats table. Added some more helper methods - e.g. OpenEntryStream (RarArchive/RarReader does not support this) Fixed up testsSilverlight Toolkit: Windows Phone Toolkit - Nov 2011 (7.1 SDK): This release is coming soon! What's new ListPicker once again works in a ScrollViewer LongListSelector bug fixes around OutOfRange exceptions, wrong ordering of items, grouping issues, and scrolling events. ItemTuple is now refactored to be the public type LongListSelectorItem to provide users better access to the values in selection changed handlers. PerformanceProgressBar binding fix for IsIndeterminate (item 9767 and others) There is no longer a GestureListener dependency with the C...New ProjectsAndrecorder: Andrecorder???Android???????,???????????????????,????????????????,????????!Android Tree Bulletin: Android bulletin reader in tree format.Bài t?p l?p môn HCI: Name: Ph?n m?m qu?n lý thu h?c phí tru?ng d?i h?c Công Nghi?p Hà N?i Basic Grid Collision sample in XNA: This project shows how to implement a basic grid collision in XNA. The project uses the XNA 4.0 framework and C#Club Manager: Club Manager is a web site for managing sport clubs / teams.Create email with encrypt text implement TEA encryption and Web Service: RahaTEA Mail is an application to send messages in secret. These applications implement TEA encryption and web serviceCRM 2011 Layers: Several .net layers to customize CRM 2011CTEF: China Tomorrow Education Foundation websitedns?????: ??c#???dns?????。????????，???????，??????。EAF: Extensibility Application FrameworkEnergy SBA: In order to compete with large companies for Federal contracts, small business need information. This application seeks to show standard methods of using remote APIs to integrate information into a Metro interface using services provided by the Small Business Administration (SBA)EPiOptimiser - Scan your EPiServer configuration to optimise start up times: EPiScanner scans your EPiServer configuration to optimise start ups by generating a recommended exclude list of assemblies to include in EPiServer framework config. It can be used on command line, as a custom build task or integrated into Visual Studio as an external tool.FreeIDS - Free Intrusion Detection System: Don't want someone to use your computer? Don't want to use a system password? Want to see when someone accessed your computer? Time/Date? FreeIDS is it!FtpServerAdministrator: FtpServerAdministrator makes it easier to administer some ftp server by code, although it can only be used for FileZilla server now. It's developed in C#.GreenPoint Online: Tools and components that help you customize an Office 365 / SharePoint Online Environment.HCC C# Workshop: This project contains the code for the exercises of the HCC C# WorkshopKsigDo - Real time view model syncing across user screens: KsigDo show real time view model syncing across user screens - using ASP.NET, Knockout and SignalR. Real time data syncing across user views *was* hard, especially in web applications. Most of the time, the second user needs to refresh the screen, to see the changes made by first user, or we need to implement some long polling that fetches the data and does the update manually. Now, with SignalR and Knockout, ASP.NET developers can take advantage of view model syncing across users, that...lineseven: ???????????????。Mail Size Labeler for GMail: A small utility that labels large e-mails on your gmail account. This utility scan you gmail account, and adds labels to large e-mail so you can clean your mailbox and free space. The labels this utility adds are: Size 1M-2M Size 2M-5M Size 5M-10M Size 10M-15M Size 15M plus Note: a single e-mail thread may get multiple labels if different e-mails of the thread fit different filters.MathService: Complex digits, standart class extentions etc.MyGameProject: gamesMySQL Connect 2 ASP.NET: Example project to show how to connect MySQL database to ASP.NET web project. IDE: Visual Studio 2010 Pro Programming language: C# Detailed information in the article here: http://epavlov.net/blog/2011/11/13/connect-to-mysql-in-visual-studio/ nl: Nutri Leaf Devomr.event.js: Simple js event injecterPastebin4DotNet: This project is an example of how to consume an API, in this case I consummed the Pastebin API.Pomelo: Pomelo is a website example.QuickDevFrameWork: ????????,??,??,????,ioc ?????postsharp?aopReadable Passphrase Generator: Generates passphrases which are (mostly) grammatically correct but nonsensical. These are easy to remember but difficult to guess (for humans or computers). Developed in C# with a KeePass plugin, console app and public API.Rosyama.ru for Windows Phone 7: ?????????? Windows Phone 7 ??? ???????? ???????? ?? ???? rosyama.ru. ?????????? ??????? ?????????? ? ???????? ????????? ???????. SimpleBatch: As the name suggests, this is a simple batch framework allowing you to define batch jobs in XML format. Thus far, contains a basic selection of processors such as the following; File Email SQL (SQL Server Client) SharePoint Document Library Custom ProcessorSite de Notícias: Projeto de faculdade que consiste na criação de um site de notícias.SPWikiProvisioning: Create update and delete SharePoint wiki pages using feature activation and deactivation handlers.SVN Automated Control With C#: I Created this libaray because I need to control Tortoise SVN automactically with out an interface for my own build server and could not find any resuilts on google to achive this task so I went about creating this libaray which dos most of the task's that I needed. I round that you could control SVN by command line so using that as my basic idear I went about coding the most common commands for SVN most of the commads are done but not all. if you like this libaray then please use it we...TremplinCMS: TremplinCMS is a CMS framework for ASP .NET 4.vlu0206sms: SMSMaker by team0206 developingWCF DataService RequestStream Access on webInvoke HTTP POST: This library provides access to the message body request stream of a WCF Data Service (formerly ADO.NET Data Service), which is not possible with the original WCF Data Service class. You are enabled passing data (e.g. Json, files) via HTTP POST to the request body. It uses the operation context (DbContext) provided by the DataService<T> class to get access to the resquest stream.WebOS: Welcome to join us to build our os projectWp7StarterDantas: Iniciando com Wp7WpfCollaborative3D: WpfCollaborative3DXNA Content Preprocessor: The XNA Content Preprocessor allows you to compile all of your XNA assets outside of your normal XNA project. This means more time building your game or app instead of your content.

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• Five Ways Enterprise 2.0 Can Transform Your Business - Q&A from the Webcast

  - by [email protected]

  A few weeks ago, Vince Casarez and I presented with KMWorld on the Five Ways Enterprise 2.0 Can Transform Your Business. It was an enjoyable, interactive webcast in which Vince and I discussed the ways Enterprise 2.0 can transform your business and more importantly, highlighted key customer examples of how to do so. If you missed the webcast, you can catch a replay here. We had a lot of audience participation in some of the polls we conducted and in the Q&A session. We weren't able to address all of the questions during the broadcast, so we attempted to answer them here: Q: Which area within your firm focuses on Web 2.0? Meaning, do you find new departments developing just to manage the web 2.0 (Twitter, Facebook, etc.) user experience or are you structuring current departments? A: There are three distinct efforts within Oracle. The first is around delivery of these Web 2.0 services for enterprise deployments. This is the focus of the WebCenter team. The second effort is injecting these Web 2.0 services into use cases that drive the different enterprise applications. This effort is focused on how to manage these external services and bring them into a cohesive flow for marketing programs, customer care, and purchasing. The third effort is how we consume these services internally to enhance Oracle's business delivery. It leverages the technologies and use cases of the first two but also pushes the envelope with regards to future directions of these other two areas. Q: In a business, Web 2.0 is mostly like action logs. How can we leverage the official process practice versus the logs of a recent action? Example: a system configuration modified last night on a call out versus the official practice that everybody would use in the morning.A: The key thing to remember is that most Web 2.0 actions / activity streams today are based on collaboration and communication type actions. At least with public social sites like Facebook and Twitter. What we're delivering as part of the WebCenter Suite are not just these types of activities but also enterprise application activities. These enterprise application activities come from different application modules: purchasing, HR, order entry, sales opportunity, etc. The actions within these systems are normally tied to a business object or process: purchase order/customer, employee or department, customer and supplier, customer and product, respectively. Therefore, the activities or "logs" as you name them are able to be "typed" so that as a viewer, you can filter or decide to see only certain types of information. In your example, you could have a view that only showed you recent "configuration" changes and this could be right next to a view that showed off the items to be watched every morning. Q: It's great to hear about customers using the software but is there any plan for future webinars to show what the products/installs look like? That would be very helpful.A: We don't have a webinar planned to show off the install process. However, we have a viewlet that's posted on Oracle Technology Network. You can see it here:http://www.oracle.com/technetwork/testcontent/wcs-install-098014.htmlAnd we've got excellent documentation that walks you through the steps here:http://download.oracle.com/docs/cd/E14571_01/install.1111/e12001/install.htmAnd there's a whole set of demos and examples of what WebCenter can do at this URL:http://www.oracle.com/technetwork/middleware/webcenter/release11-demos-097468.html Q: How do you anticipate managing metadata across the enterprise to make content findable?A: We need to first make sure we are all talking about the same thing when we use a word like "metadata". Here's why...  For a developer, metadata means information that describes key elements of the portal or application and what the portal or application can do. For content systems, metadata means key terms that provide a taxonomy or folksonomy about the information that is being indexed, ordered, and managed. For business intelligence systems, metadata means key terms that provide labels to groups of data that most non-mathematicians need to understand. And for SOA, metadata means labels for parts of the processes that business owners should understand that connect development terminology. There are also additional requirements for metadata to be available to the team building these new solutions as well as requirements to make this metadata available to the running system. These requirements are often separated by "design time" and "run time" respectively. So clearly, a general goal of managing metadata across the enterprise is very challenging. We've invested a huge amount of resources around Oracle Metadata Services (MDS) to be able to provide a more generic system for all of these elements. No other vendor has anything like this technology foundation in their products. This provides a huge benefit to our customers as they will now be able to find content, processes, people, and information from a common set of search interfaces with consistent enterprise wide results. Q: Can you give your definition of terms as to document and content, please?A: Content applies to a broad category of information from Word documents, presentations and reports through attachments to invoices and/or purchase orders. Content is essentially any type of digital asset including images, video, and voice. A document is just one type of content. Q: Do you have special integration tools to realize an interaction between UCM and WebCenter Spaces/Services?A: Yes, we've dedicated a whole team of engineers to exploit the key features of Oracle UCM within WebCenter.  While ensuring that WebCenter can connect to other non-Oracle systems, we've made sure that with the combined set of Oracle technology, no other solution can match the combined power and integration.  This is part of the Oracle Fusion Middleware strategy which is to provide best in class capabilities for Content and Portals.  When combined together, the synergy between the two products enables users to quickly add capabilities when they are needed.  For example, simple document sharing is part of the combined product offering, but if legal discovery or archiving is required, Oracle UCM product includes these capabilities that can be quickly added.  There's no need to move content around or add another system to support this, it's just a feature that gets turned on within Oracle UCM. Q: All customers have some interaction with their applications and have many older versions, how do you see some of these new Enterprise 2.0 capabilities adding value to existing enterprise application deployments?A: Just as Service Oriented Architectures allowed for connecting the processes of different applications systems to work together, there's a need for a similar approach with regards to these enterprise 2.0 capabilities. Oracle WebCenter is built on a core architecture that allows for SOA of these Enterprise 2.0 services so that one set of scalable services can be used and integrated directly into any type of application. In this way, users can get immediate value out of the Enterprise 2.0 capabilities without having to wait for the next major release or upgrade. These centrally managed WebCenter services expose a set of standard interfaces that make it extremely easy to add them into existing applications no matter what technology the application has been implemented. Q: We've heard about Oracle Next Generation applications called "Fusion Applications", can you tell me how all this works together?A: Oracle WebCenter powers the core collaboration and social computing services found within Fusion Applications. It is the core user experience technology for how all the application screens have been implemented. And the core concept of task flows allows for all the Fusion Applications modules to be adaptable and composable by business users and IT without needing to be a professional developer. Oracle WebCenter is at the heart of the new Fusion Applications. In addition, the same patterns and technologies are now being added to the existing applications including JD Edwards, Siebel, Peoplesoft, and eBusiness Suite. The core technology enables all these customers to have a much smoother upgrade path to Fusion Applications. They get immediate benefits of injecting new user interactions into their existing applications without having to completely move to Fusion Applications. And then when the time comes, their users will already be well versed in how the new capabilities work. Q: Does any of this work with non Oracle software? Other databases? Other application servers? etc.A: We have made sure that Oracle WebCenter delivers the broadest set of development choices so that no matter what technology you developers are using, WebCenter capabilities can be quickly and easily added to the site or application. In addition, we have certified Oracle WebCenter to run against non-Oracle databases like DB2 and SQLServer. We have stated plans for certification against MySQL as well. Later in CY 2011, Oracle will provide certification on non-Oracle application servers such as WebSphere and JBoss. Q: How do we balance User and IT requirements in regards to Enterprise 2.0 technologies?A: Wrong decisions are often made because employee knowledge is not tapped efficiently and opportunities to innovate are often missed because the right people do not work together. Collaboration amongst workers in the right business context is critical for success. While standalone Enterprise 2.0 technologies can improve collaboration for collaboration's sake, using social collaboration tools in the context of business applications and processes will improve business responsiveness and lead companies to a more competitive position. As these systems become more mission critical it is essential that they maintain the highest level of performance and availability while scaling to support larger communities. Q: What are the ways in which Enterprise 2.0 can improve business responsiveness?A: With a wide range of Enterprise 2.0 tools in the marketplace, CIOs need to deploy solutions that will meet the requirements from users as well as address the requirements from IT. Workers want a next-generation user experience that is personalized and aggregates their daily tools and tasks, while IT needs to ensure the solution is secure, scalable, flexible, reliable and easily integrated with existing systems. An open and integrated approach to deploying portals, content management, and collaboration can enhance your business by addressing both the needs of knowledge workers for better information and the IT mandate to conserve resources by simplifying, consolidating and centralizing infrastructure and administration.  

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• Sliding collision response

  - by dbostream

  I have been reading plenty of tutorials about sliding collision responses yet I am not able to implement it properly in my project. What I want to do is make a puck slide along the rounded corner boards of a hockey rink. In my latest attempt the puck does slide along the boards but there are some strange velocity behaviors. First of all the puck slows down a lot pretty much right away and then it slides for awhile and stops before exiting the corner. Even if I double the speed I get a similar behavior and the puck does not make it out of the corner. I used some ideas from this document http://www.peroxide.dk/papers/collision/collision.pdf. This is what I have: Update method called from the game loop when it is time to update the puck (I removed some irrelevant parts). I use two states (current, previous) which are used to interpolate the position during rendering. public override void Update(double fixedTimeStep) { /* Acceleration is set to 0 for now. */ Acceleration.Zero(); PreviousState = CurrentState; _collisionRecursionDepth = 0; CurrentState.Position = SlidingCollision(CurrentState.Position, CurrentState.Velocity * fixedTimeStep + 0.5 * Acceleration * fixedTimeStep * fixedTimeStep); /* Should not this be affected by a sliding collision? and not only the position. */ CurrentState.Velocity = CurrentState.Velocity + Acceleration * fixedTimeStep; Heading = Vector2.NormalizeRet(CurrentState.Velocity); } private Vector2 SlidingCollision(Vector2 position, Vector2 velocity) { if(_collisionRecursionDepth > 5) return position; bool collisionFound = false; Vector2 futurePosition = position + velocity; Vector2 intersectionPoint = new Vector2(); Vector2 intersectionPointNormal = new Vector2(); /* I did not include the collision detection code, if a collision is detected the intersection point and normal in that point is returned. */ if(!collisionFound) return futurePosition; /* If no collision was detected it is safe to move to the future position. */ /* It is not exactly the intersection point, but slightly before. */ Vector2 newPosition = intersectionPoint; /* oldVelocity is set to the distance from the newPosition(intersection point) to the position it had moved to had it not collided. */ Vector2 oldVelocity = futurePosition - newPosition; /* Project the distance left to move along the intersection normal. */ Vector2 newVelocity = oldVelocity - intersectionPointNormal * oldVelocity.DotProduct(intersectionPointNormal); if(newVelocity.LengthSq() < 0.001) return newPosition; /* If almost no speed, no need to continue. */ _collisionRecursionDepth++; return SlidingCollision(newPosition, newVelocity); } What am I doing wrong with the velocity? I have been staring at this for very long so I have gone blind. I have tried different values of recursion depth but it does not seem to make it better. Let me know if you need more information. I appreciate any help. EDIT: A combination of Patrick Hughes' and teodron's answers solved the velocity problem (I think), thanks a lot! This is the new code: I decided to use a separate recursion method now too since I don't want to recalculate the acceleration in each recursion. public override void Update(double fixedTimeStep) { Acceleration.Zero();// = CalculateAcceleration(fixedTimeStep); PreviousState = new MovingEntityState(CurrentState.Position, CurrentState.Velocity); CurrentState = SlidingCollision(CurrentState, fixedTimeStep); Heading = Vector2.NormalizeRet(CurrentState.Velocity); } private MovingEntityState SlidingCollision(MovingEntityState state, double timeStep) { bool collisionFound = false; /* Calculate the next position given no detected collision. */ Vector2 futurePosition = state.Position + state.Velocity * timeStep; Vector2 intersectionPoint = new Vector2(); Vector2 intersectionPointNormal = new Vector2(); /* I did not include the collision detection code, if a collision is detected the intersection point and normal in that point is returned. */ /* If no collision was detected it is safe to move to the future position. */ if (!collisionFound) return new MovingEntityState(futurePosition, state.Velocity); /* Set new position to the intersection point (slightly before). */ Vector2 newPosition = intersectionPoint; /* Project the new velocity along the intersection normal. */ Vector2 newVelocity = state.Velocity - 1.90 * intersectionPointNormal * state.Velocity.DotProduct(intersectionPointNormal); /* Calculate the time of collision. */ double timeOfCollision = Math.Sqrt((newPosition - state.Position).LengthSq() / (futurePosition - state.Position).LengthSq()); /* Calculate new time step, remaining time of full step after the collision * current time step. */ double newTimeStep = timeStep * (1 - timeOfCollision); return SlidingCollision(new MovingEntityState(newPosition, newVelocity), newTimeStep); } Even though the code above seems to slide the puck correctly please have a look at it. I have a few questions, if I don't multiply by 1.90 in the newVelocity calculation it doesn't work (I get a stack overflow when the puck enters the corner because the timeStep decreases very slowly - a collision is found early in every recursion), why is that? what does 1.90 really do and why 1.90? Also I have a new problem, the puck does not move parallell to the short side after exiting the curve; to be more exact it moves outside the rink (I am not checking for any collisions with the short side at the moment). When I perform the collision detection I first check that the puck is in the correct quadrant. For example bottom-right corner is quadrant four i.e. circleCenter.X < puck.X && circleCenter.Y puck.Y is this a problem? or should the short side of the rink be the one to make the puck go parallell to it and not the last collision in the corner? EDIT2: This is the code I use for collision detection, maybe it has something to do with the fact that I can't make the puck slide (-1.0) but only reflect (-2.0): /* Point is the current position (not the predicted one) and quadrant is 4 for the bottom-right corner for example. */ if (GeometryHelper.PointInCircleQuadrant(circleCenter, circleRadius, state.Position, quadrant)) { /* The line is: from = state.Position, to = futurePosition. So a collision is detected when from is inside the circle and to is outside. */ if (GeometryHelper.LineCircleIntersection2d(state.Position, futurePosition, circleCenter, circleRadius, intersectionPoint, quadrant)) { collisionFound = true; /* Set the intersection point to slightly before the real intersection point (I read somewhere this was good to do because of floting point precision, not sure exactly how much though). */ intersectionPoint = intersectionPoint - Vector2.NormalizeRet(state.Velocity) * 0.001; /* Normal at the intersection point. */ intersectionPointNormal = Vector2.NormalizeRet(circleCenter - intersectionPoint) } } When I set the intersection point, if I for example use 0.1 instead of 0.001 the puck travels further before it gets stuck, but for all values I have tried (including 0 - the real intersection point) it gets stuck somewhere (but I necessarily not get a stack overflow). Can something in this part be the cause of my problem? I can see why I get the stack overflow when using -1.0 when calculating the new velocity vector; but not how to solve it. I traced the time steps used in the recursion (initial time step is always 1/60 ~ 0.01666): Recursion depth Time step next recursive call [Start recursion, time step ~ 0.016666] 0 0,000985806527246773 [No collision, stop recursion] [Start recursion, time step ~ 0.016666] 0 0,0149596704364629 1 0,0144883449376379 2 0,0143155612984837 3 0,014224925727213 4 0,0141673917461608 5 0,0141265435314026 6 0,0140953966184117 7 0,0140704653746625 ...and so on. As you can see the collision is detected early in every recursive call which means the next time step decreases very slowly thus the recursion depth gets very big - stack overflow.

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• T-SQL Tuesday #31 - Logging Tricks with CONTEXT_INFO

  - by Most Valuable Yak (Rob Volk)

  This month's T-SQL Tuesday is being hosted by Aaron Nelson [b | t], fellow Atlantan (the city in Georgia, not the famous sunken city, or the resort in the Bahamas) and covers the topic of logging (the recording of information, not the harvesting of trees) and maintains the fine T-SQL Tuesday tradition begun by Adam Machanic [b | t] (the SQL Server guru, not the guy who fixes cars, check the spelling again, there will be a quiz later). This is a trick I learned from Fernando Guerrero [b | t] waaaaaay back during the PASS Summit 2004 in sunny, hurricane-infested Orlando, during his session on Secret SQL Server (not sure if that's the correct title, and I haven't used parentheses in this paragraph yet).  CONTEXT_INFO is a neat little feature that's existed since SQL Server 2000 and perhaps even earlier.  It lets you assign data to the current session/connection, and maintains that data until you disconnect or change it.  In addition to the CONTEXT_INFO() function, you can also query the context_info column in sys.dm_exec_sessions, or even sysprocesses if you're still running SQL Server 2000, if you need to see it for another session. While you're limited to 128 bytes, one big advantage that CONTEXT_INFO has is that it's independent of any transactions.  If you've ever logged to a table in a transaction and then lost messages when it rolled back, you can understand how aggravating it can be.  CONTEXT_INFO also survives across multiple SQL batches (GO separators) in the same connection, so for those of you who were going to suggest "just log to a table variable, they don't get rolled back":  HA-HA, I GOT YOU!  Since GO starts a new batch all variable declarations are lost. Here's a simple example I recently used at work.  I had to test database mirroring configurations for disaster recovery scenarios and measure the network throughput.  I also needed to log how long it took for the script to run and include the mirror settings for the database in question.  I decided to use AdventureWorks as my database model, and Adam Machanic's Big Adventure script to provide a fairly large workload that's repeatable and easily scalable.  My test would consist of several copies of AdventureWorks running the Big Adventure script while I mirrored the databases (or not). Since Adam's script contains several batches, I decided CONTEXT_INFO would have to be used.  As it turns out, I only needed to grab the start time at the beginning, I could get the rest of the data at the end of the process.   The code is pretty small: declare @time binary(128)=cast(getdate() as binary(8)) set context_info @time   ... rest of Big Adventure code ...   go use master; insert mirror_test(server,role,partner,db,state,safety,start,duration) select @@servername, mirroring_role_desc, mirroring_partner_instance, db_name(database_id), mirroring_state_desc, mirroring_safety_level_desc, cast(cast(context_info() as binary(8)) as datetime), datediff(s,cast(cast(context_info() as binary(8)) as datetime),getdate()) from sys.database_mirroring where db_name(database_id) like 'Adv%';   I declared @time as a binary(128) since CONTEXT_INFO is defined that way.  I couldn't convert GETDATE() to binary(128) as it would pad the first 120 bytes as 0x00.  To keep the CAST functions simple and avoid using SUBSTRING, I decided to CAST GETDATE() as binary(8) and let SQL Server do the implicit conversion.  It's not the safest way perhaps, but it works on my machine. :) As I mentioned earlier, you can query system views for sessions and get their CONTEXT_INFO.  With a little boilerplate code this can be used to monitor long-running procedures, in case you need to kill a process, or are just curious  how long certain parts take.  In this example, I added code to Adam's Big Adventure script to set CONTEXT_INFO messages at strategic places I want to monitor.  (His code is in UPPERCASE as it was in the original, mine is all lowercase): declare @msg binary(128) set @msg=cast('Altering bigProduct.ProductID' as binary(128)) set context_info @msg go ALTER TABLE bigProduct ALTER COLUMN ProductID INT NOT NULL GO set context_info 0x0 go declare @msg1 binary(128) set @msg1=cast('Adding pk_bigProduct Constraint' as binary(128)) set context_info @msg1 go ALTER TABLE bigProduct ADD CONSTRAINT pk_bigProduct PRIMARY KEY (ProductID) GO set context_info 0x0 go declare @msg2 binary(128) set @msg2=cast('Altering bigTransactionHistory.TransactionID' as binary(128)) set context_info @msg2 go ALTER TABLE bigTransactionHistory ALTER COLUMN TransactionID INT NOT NULL GO set context_info 0x0 go declare @msg3 binary(128) set @msg3=cast('Adding pk_bigTransactionHistory Constraint' as binary(128)) set context_info @msg3 go ALTER TABLE bigTransactionHistory ADD CONSTRAINT pk_bigTransactionHistory PRIMARY KEY NONCLUSTERED(TransactionID) GO set context_info 0x0 go declare @msg4 binary(128) set @msg4=cast('Creating IX_ProductId_TransactionDate Index' as binary(128)) set context_info @msg4 go CREATE NONCLUSTERED INDEX IX_ProductId_TransactionDate ON bigTransactionHistory(ProductId,TransactionDate) INCLUDE(Quantity,ActualCost) GO set context_info 0x0   This doesn't include the entire script, only those portions that altered a table or created an index.  One annoyance is that SET CONTEXT_INFO requires a literal or variable, you can't use an expression.  And since GO starts a new batch I need to declare a variable in each one.  And of course I have to use CAST because it won't implicitly convert varchar to binary.  And even though context_info is a nullable column, you can't SET CONTEXT_INFO NULL, so I have to use SET CONTEXT_INFO 0x0 to clear the message after the statement completes.  And if you're thinking of turning this into a UDF, you can't, although a stored procedure would work. So what does all this aggravation get you?  As the code runs, if I want to see which stage the session is at, I can run the following (assuming SPID 51 is the one I want): select CAST(context_info as varchar(128)) from sys.dm_exec_sessions where session_id=51   Since SQL Server 2005 introduced the new system and dynamic management views (DMVs) there's not as much need for tagging a session with these kinds of messages.  You can get the session start time and currently executing statement from them, and neatly presented if you use Adam's sp_whoisactive utility (and you absolutely should be using it).  Of course you can always use xp_cmdshell, a CLR function, or some other tricks to log information outside of a SQL transaction.  All the same, I've used this trick to monitor long-running reports at a previous job, and I still think CONTEXT_INFO is a great feature, especially if you're still using SQL Server 2000 or want to supplement your instrumentation.  If you'd like an exercise, consider adding the system time to the messages in the last example, and an automated job to query and parse it from the system tables.  That would let you track how long each statement ran without having to run Profiler. #TSQL2sDay

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• Setup Guide for updating local system and the repository with the incremental Solaris 11.1 SRU

  - by Gurubalan

  This guide covers the steps to implement the following setup. I. Updating the local system from Solaris 11.1 to Solaris 11.1 SRU 16.5II. Setting up local system as an IPS Repository Server (HTTP interface)III. Updating the local repository with the incremental Solaris 11.1 SRU 16.5I. Updating the local system from Solaris 11.1 to Solaris 11.1 SRU 16.5We assume that the local system is currently installed with Solaris 11.1 GA and the system doesn't have internet connectivity.What I have:1. Two parts of full repo iso files downloaded from http://www.oracle.com/technetwork/server-storage/solaris11/downloads/index.html. Both files are concatenated to a single file using the following command. $ cat sol-11_1-repo-full.iso-a sol-11_1-repo-full.iso-b > sol-11_1-repo-full.iso I suggest to verify the downloaded file against its md5checksum value [http://download.oracle.com/otn/solaris/11_1/md5sum.txt] using the following command digest -a md5 <file-name>  // the output of this command should match the original checksum value for that file.2. Incremental repo sol-11_1_16_5_0-incr-repo.iso downloaded from MOS [Patch 18269379: ORACLE SOLARIS 11.1.16.5.0 REPO ISO IMAGE (SPARC/X86 (64-BIT)]. You can get the checksum value of incremental repo iso by clicking the check box "show digest details" when you download the file.3. The local system IP is 192.168.10.10 & port 81 is reserved for repo serverPlease note that this repo file (either full or incremental) is common for both SPARC and X86(64BIT).Steps to update the local system: 1. #mounting s11.1 full repo iso to mnt        $ mount -F hsfs /soft/sol-11_1-repo-full.iso /mnt 2. Setting the pkg publisher to full repo source         $ pkg set-publisher -g file:///mnt/repo solaris 3. Perform the update of the packages.        $ pkg updateII. Setting up local system (Oracle Solaris 11.1) as an IPS Repository Server(HTTP interface):Please note that we have already mounted the full repo iso at /mnt    1. # copying /mnt permanently to the disk location at /s11.1        #zfs create -o atime=off -o mountpoint=/s11.1 rpool/s11.1        #rsync -aP /mnt/* /s11.1     2. #unmounting mnt         #umount /mnt3. To allow clients to access the local repository via HTTP, enable the application/pkg/server Service Management Facility (SMF) service.        svccfg -s application/pkg/server setprop pkg/inst_root=<data_source>/repo        eg: $svccfg -s application/pkg/server setprop pkg/inst_root=/s11.1/repo4. Setting port# to 81      svccfg -s application/pkg/server setprop pkg/port=<port_number>      eg: svccfg -s application/pkg/server setprop pkg/port="81"5a. Enable the pkg/server service (if the service is disabled)     $svcs pkg/server     STATE          STIME    FMRI     disabled        19:55:03 svc:/application/pkg/server:default      $svcadm enable pkg/server5b. Refresh/Restart the service, if it is already online       $svcadm refresh application/pkg/server       $svcadm restart application/pkg/server6. Setting pkg publisher on repo server and repo clients:      pkg set-publisher -G '*' -g http://<ip>:<port> solaris      eg: $pkg set-publisher -G '*' -g 'http://192.168.10.10:81' solaris7. Verify the Solaris 11.1 version from the repository         $pkgrepo list -s http://192.168.10.10:81 | grep entire         solaris   entire     0.5.11,5.11-0.175.1.0.0.24.2:20120919T190135Z You will have multiple row entries if the repository is setup with incremental SRUs.III. Updating the local repository with the incremental Solaris 11.1 SRU 16.51. #mounting s11.1 incremental SRU repo iso to mnt        $ mount -F hsfs <full_path_to>/sol-11_1_sruN_bldnum_respinnum-incr-repo.iso  /mnt        $ mount -F hsfs /soft/sol-11_1_16_5_0-incr-repo.iso /mnt2. Updating the local repository        $pkgrecv -s  /mnt/repo -d /s11.1/repo '*'3. Building a Search Index    $pkgrepo -s /s11.1/repo refresh     Initiating repository refresh.4. Refresh/Restart the service       $svcadm refresh svc:/application/pkg/server       $svcadm restart svc:/application/pkg/server5. Verify the repo has the incremental SRU as well.       # pkgrepo list -s http://192.168.10.10:81 | grep entire        solaris   entire      0.5.11,5.11-0.175.1.16.0.5.0:20140218T165248Z       solaris   entire      0.5.11,5.11-0.175.1.0.0.24.2:20120919T190135Z

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• SQL University: What and why of database testing

  - by Mladen Prajdic

  This is a post for a great idea called SQL University started by Jorge Segarra also famously known as SqlChicken on Twitter. It’s a collection of blog posts on different database related topics contributed by several smart people all over the world. So this week is mine and we’ll be talking about database testing and refactoring. In 3 posts we’ll cover: SQLU part 1 - What and why of database testing SQLU part 2 - What and why of database refactoring SQLU part 2 – Tools of the trade With that out of the way let us sharpen our pencils and get going. Why test a database The sad state of the industry today is that there is very little emphasis on testing in general. Test driven development is still a small niche of the programming world while refactoring is even smaller. The cause of this is the inability of developers to convince themselves and their managers that writing tests is beneficial. At the moment they are mostly viewed as waste of time. This is because the average person (let’s not fool ourselves, we’re all average) is unable to think about lower future costs in relation to little more current work. It’s orders of magnitude easier to know about the current costs in relation to current amount of work. That’s why programmers convince themselves testing is a waste of time. However we have to ask ourselves what tests are really about? Maybe finding bugs? No, not really. If we introduce bugs, we’re likely to write test around those bugs too. But yes we can find some bugs with tests. The main point of tests is to have reproducible repeatability in our systems. By having a code base largely covered by tests we can know with better certainty what a small code change can break in other parts of the system. By having repeatability we can make code changes with confidence, since we know we’ll see what breaks in other tests. And here comes the inability to estimate future costs. By spending just a few more hours writing those tests we’d know instantly what broke where. Imagine we fix a reported bug. We check-in the code, deploy it and the users are happy. Until we get a call 2 weeks later about a certain monthly process has stopped working. What we don’t know is that this process was developed by a long gone coworker and for some reason it relied on that same bug we’ve happily fixed. There’s no way we could’ve known that. We say OK and go in and fix the monthly process. But what we have no clue about is that there’s this ETL job that relied on data from that monthly process. Now that we’ve fixed the process it’s giving unexpected (yet correct since we fixed it) data to the ETL job. So we have to fix that too. But there’s this part of the app we coded that relies on data from that exact ETL job. And just like that we enter the “Loop of maintenance horror”. With the loop eventually comes blame. Here’s a nice tip for all developers and DBAs out there: If you make a mistake man up and admit to it. All of the above is valid for any kind of software development. Keeping this in mind the database is nothing other than just a part of the application. But a big part! One reason why testing a database is even more important than testing an application is that one database is usually accessed from multiple applications and processes. This makes it the central and vital part of the enterprise software infrastructure. Knowing all this can we really afford not to have tests? What to test in a database Now that we’ve decided we’ll dive into this testing thing we have to ask ourselves what needs to be tested? The short answer is: everything. The long answer is: read on! There are 2 main ways of doing tests: Black box and White box testing. Black box testing means we have no idea how the system internals are built and we only have access to it’s inputs and outputs. With it we test that the internal changes to the system haven’t caused the input/output behavior of the system to change. The most important thing to test here are the edge conditions. It’s where most programs break. Having good edge condition tests we can be more confident that the systems changes won’t break. White box testing has the full knowledge of the system internals. With it we test the internal system changes, different states of the application, etc… White and Black box tests should be complementary to each other as they are very much interconnected. Testing database routines includes testing stored procedures, views, user defined functions and anything you use to access the data with. Database routines are your input/output interface to the database system. They count as black box testing. We test then for 2 things: Data and schema. When testing schema we only care about the columns and the data types they’re returning. After all the schema is the contract to the out side systems. If it changes we usually have to change the applications accessing it. One helpful T-SQL command when doing schema tests is SET FMTONLY ON. It tells the SQL Server to return only empty results sets. This speeds up tests because it doesn’t return any data to the client. After we’ve validated the schema we have to test the returned data. There no other way to do this but to have expected data known before the tests executes and comparing that data to the database routine output. Testing Authentication and Authorization helps us validate who has access to the SQL Server box (Authentication) and who has access to certain database objects (Authorization). For desktop applications and windows authentication this works well. But the biggest problem here are web apps. They usually connect to the database as a single user. Please ensure that that user is not SA or an account with admin privileges. That is just bad. Load testing ensures us that our database can handle peak loads. One often overlooked tool for load testing is Microsoft’s OSTRESS tool. It’s part of RML utilities (x86, x64) for SQL Server and can help determine if our database server can handle loads like 100 simultaneous users each doing 10 requests per second. SQL Profiler can also help us here by looking at why certain queries are slow and what to do to fix them.   One particular problem to think about is how to begin testing existing databases. First thing we have to do is to get to know those databases. We can’t test something when we don’t know how it works. To do this we have to talk to the users of the applications accessing the database, run SQL Profiler to see what queries are being run, use existing documentation to decipher all the object relationships, etc… The way to approach this is to choose one part of the database (say a logical grouping of tables that go together) and filter our traces accordingly. Once we’ve done that we move on to the next grouping and so on until we’ve covered the whole database. Then we move on to the next one. Database Testing is a topic that we can spent many hours discussing but let this be a nice intro to the world of database testing. See you in the next post.

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• Rebuilding CoasterBuzz, Part III: The architecture using the "Web stack of love"

  - by Jeff

  This is the third post in a series about rebuilding one of my Web sites, which has been around for 12 years. I hope to relaunch in the next month or two. More: Part I: Evolution, and death to WCF Part II: Hot data objects I finally hit a point in the re-do of CoasterBuzz where I feel like the major pieces are in place... rewritten, ported and what not, so that I can focus now on front-end design and more interesting creative problems. I've been asked on more than one occasion (OK, just twice) what's going on under the covers, so I figure this might be a good time to explain the overall architecture. As it turns out, I'm using a whole lof of the "Web stack of love," as Scott Hanselman likes to refer to it. Oh that Hanselman. First off, at the center of it all, is BizTalk. Just kidding. That's "enterprise architecture" humor, where every discussion starts with how they'll use BizTalk. Here are the bigger moving parts: It's fairly straight forward. A common library lives in a number of Web apps, all of which are (or will be) powered by ASP.NET MVC 4. They all talk to the same database. There is the main Web site, which also has the endpoint for the Silverlight-based Feed app. The cstr.bz site handles redirects, which are generated when news items are published and sent to Twitter. Facebook publishing is handled via the RSS Graffiti Facebook app. The API site handles requests from the Windows Phone app. The main site depends very heavily on POP Forums, the open source, MVC-based forum I maintain. It serves a number of functions, primarily handling users. These user objects serve in non-forum roles to handle things like news and database contributions, maintaining track records (coaster nerd for "list of rides I've been on") and, perhaps most importantly, paid club memberships. Before I get into more specifics, note that the "glue" for everything is Ninject, the dependency injection framework. I actually prefer StructureMap these days, but I started with Ninject in POP Forums a long time ago. POP Forums has a static class, PopForumsActivation, that new's up an instance of the container, and you can call it from where ever. The downside is that the forums require Ninject in your MVC app as the default dependency resolver. At some point, I'll decouple it, but for now it's not in the way. In the general sense, the entire set of apps follow a repository-service-controller-view pattern. Repos just do data access, service classes do business logic, controllers compose and route, views view. The forum also provides Scoring Game functionality. The Scoring Game is a reasonably abstract framework to award users points based on certain actions, and then award achievements when a certain number of point events happen. For example, the forum already awards a point when someone plus-one's a post you made. You can set up an achievement that says, "Give the user an award when they've had 100 posts plus'd." It also does zero-point entries into the ledger, so if you make a post, you could award an achievement based on 100 posts made. Wiring in the scoring game to CoasterBuzz functionality is just a matter of going to the Ninject container and getting an instance of the event publisher, and passing it events. Forum adapters were introduced into POP Forums a few versions ago, and they can intercept the model generated for forum topic lists and threads and designate an alternate view. These are used to make the "Day in Pictures" forum, where users can upload photos as frame-by-frame photo threads. Another adapter adds an association UI, so users can associate specific amusement parks with their trip report posts. The Silverlight-based Feed app talks to a simple JSON endpoint in the main app. This uses an underlying library I wrote ages ago, simply called Feeds, that aggregates event information. You inherit from a base class that creates instances of a publisher interface, and then use that class to send it an event type and any number of data fields. Feeds has two publishers: One is to the database, and that's used for the endpoint that talks to the Silverlight app. The second publisher publishes to Twitter, if the event is of the type "news." The wiring is a little strange, because for the new posts and topics events, I'm actually pulling out the forum repository classes from the Ninject container and replacing them with overridden methods to publish. I should probably be doing this at the service class level, but whatever. It's my mess. cstr.bz doesn't do anything interesting. It looks up the path, and if it has a match, does a 301 redirect to the long URL. The API site just serves up JSON for the Windows Phone app. The Windows Phone app is Silverlight, of course, and there isn't much to it. It does use the control toolkit, but beyond that, it relies on a simple class that creates a Webclient and calls the server for JSON to deserialize. The same class is now used by the Feed app, which used to use WCF. Simple is better. Data access in POP Forums is all straight SQL, because a lot of it was ported from the ASP.NET version. Most CoasterBuzz data access is handled by the Entity Framework, using the code-first model. The context class in this case does a lot of work to make sure that the table and key mapping works, since much of it breaks from the normal conventions of EF. One of the more powerful things you can do with EF, once you understand the little gotchas, is split tables by row into different entities. For example, a roller coaster photo has everything in the same row, including the metadata, the thumbnail bytes and the image itself. Obviously, if you want to get a list of photos to iterate over in a view, you don't want to get the image data. The use of navigation properties makes it easier to get just what you want. The front end includes Razor views in MVC, and jQuery is used for client-side goodness. I'm also using jQuery UI in a few places, for tabs, a dialog box and autocomplete. I'm also, tentatively, using jQuery Mobile. I've already ported most forum views to Mobile, but they need some work as v1.1 isn't finished yet. I'm not sure if I'll ship CoasterBuzz with mobile views or not yet. It's on the radar, but not something in my delivery criteria. That covers all of the big frameworks in play. Next time I hope to talk more about the front-end experience, which to me is where most of the fun is these days. Hoping to launch in the next month or two. Getting tired of looking at the old site!

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• Elegance, thy Name is jQuery

  - by SGWellens

  So, I'm browsing though some questions over on the Stack Overflow website and I found a good jQuery question just a few minutes old. Here is a link to it. It was a tough question; I knew that by answering it, I could learn new stuff and reinforce what I already knew: Reading is good, doing is better. Maybe I could help someone in the process too. I cut and pasted the HTML from the question into my Visual Studio IDE and went back to Stack Overflow to reread the question. Dang, someone had already answered it! And it was a great answer. I never even had a chance to start analyzing the issue. Now I know what a one-legged man feels like in an ass-kicking contest. Nevertheless, since the question and answer were so interesting, I decided to dissect them and learn as much as possible. The HTML consisted of some divs separated by h3 headings.  Note the elements are laid out sequentially with no programmatic grouping: <h3 class="heading">Heading 1</h3> <div>Content</div> <div>More content</div> <div>Even more content</div><h3 class="heading">Heading 2</h3> <div>some content</div> <div>some more content</div><h3 class="heading">Heading 3</h3> <div>other content</div></form></body>  The requirement was to wrap a div around each h3 heading and the subsequent divs grouping them into sections. Why? I don't know, I suppose if you screen-scrapped some HTML from another site, you might want to reformat it before displaying it on your own. Anyways… Here is the marvelously, succinct posted answer: $('.heading').each(function(){ $(this).nextUntil('.heading').andSelf().wrapAll('<div class="section">');}); I was familiar with all the parts except for nextUntil and andSelf. But, I'll analyze the whole answer for completeness. I'll do this by rewriting the posted answer in a different style and adding a boat-load of comments: function Test(){ // $Sections is a jQuery object and it will contain three elements var $Sections = $('.heading'); // use each to iterate over each of the three elements $Sections.each(function () { // $this is a jquery object containing the current element // being iterated var $this = $(this); // nextUntil gets the following sibling elements until it reaches // an element with the CSS class 'heading' // andSelf adds in the source element (this) to the collection $this = $this.nextUntil('.heading').andSelf(); // wrap the elements with a div $this.wrapAll('<div class="section" >'); });}  The code here doesn't look nearly as concise and elegant as the original answer. However, unless you and your staff are jQuery masters, during development it really helps to work through algorithms step by step. You can step through this code in the debugger and examine the jQuery objects to make sure one step is working before proceeding on to the next. It's much easier to debug and troubleshoot when each logical coding step is a separate line of code. Note: You may think the original code runs much faster than this version. However, the time difference is trivial: Not enough to worry about: Less than 1 millisecond (tested in IE and FF). Note: You may want to jam everything into one line because it results in less traffic being sent to the client. That is true. However, most Internet servers now compress HTML and JavaScript by stripping out comments and white space (go to Bing or Google and view the source). This feature should be enabled on your server: Let the server compress your code, you don't need to do it. Free Career Advice: Creating maintainable code is Job One—Maximum Priority—The Prime Directive. If you find yourself suddenly transferred to customer support, it may be that the code you are writing is not as readable as it could be and not as readable as it should be. Moving on… I created a CSS class to enhance the results: .section{ background-color: yellow; border: 2px solid black; margin: 5px;} Here is the rendered output before:   …and after the jQuery code runs.   Pretty Cool! But, while playing with this code, the logic of nextUntil began to bother me: What happens in the last section? What stops elements from being collected since there are no more elements with the .heading class? The answer is nothing.  In this case it stopped collecting elements because it was at the end of the page.  But what if there were additional HTML elements? I added an anchor tag and another div to the HTML: <h3 class="heading">Heading 1</h3> <div>Content</div> <div>More content</div> <div>Even more content</div><h3 class="heading">Heading 2</h3> <div>some content</div> <div>some more content</div><h3 class="heading">Heading 3</h3> <div>other content</div><a>this is a link</a><div>unrelated div</div> </form></body> The code as-is will include both the anchor and the unrelated div. This isn't what we want.   My first attempt to correct this used the filter parameter of the nextUntil function: nextUntil('.heading', 'div')  This will only collect div elements. But it merely skipped the anchor tag and it still collected the unrelated div:   The problem is we need a way to tell the nextUntil function when to stop. CSS selectors to the rescue! nextUntil('.heading, a')  This tells nextUntil to stop collecting elements when it gets to an element with a .heading class OR when it gets to an anchor tag. In this case it solved the problem. FYI: The comma operator in a CSS selector allows multiple criteria.   Bingo! One final note, we could have broken the code down even more: We could have replaced the andSelf function here: $this = $this.nextUntil('.heading, a').andSelf(); With this: // get all the following siblings and then add the current item$this = $this.nextUntil('.heading, a');$this.add(this);  But in this case, the andSelf function reads real nice. In my opinion. Here's a link to a jsFiddle if you want to play with it. I hope someone finds this useful Steve Wellens CodeProject

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• SQL University: What and why of database refactoring

  - by Mladen Prajdic

  This is a post for a great idea called SQL University started by Jorge Segarra also famously known as SqlChicken on Twitter. It’s a collection of blog posts on different database related topics contributed by several smart people all over the world. So this week is mine and we’ll be talking about database testing and refactoring. In 3 posts we’ll cover: SQLU part 1 - What and why of database testing SQLU part 2 - What and why of database refactoring SQLU part 3 - Tools of the trade This is a second part of the series and in it we’ll take a look at what database refactoring is and why do it. Why refactor a database To know why refactor we first have to know what refactoring actually is. Code refactoring is a process where we change module internals in a way that does not change that module’s input/output behavior. For successful refactoring there is one crucial thing we absolutely must have: Tests. Automated unit tests are the only guarantee we have that we haven’t broken the input/output behavior before refactoring. If you haven’t go back ad read my post on the matter. Then start writing them. Next thing you need is a code module. Those are views, UDFs and stored procedures. By having direct table access we can kiss fast and sweet refactoring good bye. One more point to have a database abstraction layer. And no, ORM’s don’t fall into that category. But also know that refactoring is NOT adding new functionality to your code. Many have fallen into this trap. Don’t be one of them and resist the lure of the dark side. And it’s a strong lure. We developers in general love to add new stuff to our code, but hate fixing our own mistakes or changing existing code for no apparent reason. To be a good refactorer one needs discipline and focus. Now we know that refactoring is all about changing inner workings of existing code. This can be due to performance optimizations, changing internal code workflows or some other reason. This is a typical black box scenario to the outside world. If we upgrade the car engine it still has to drive on the road (preferably faster) and not fly (no matter how cool that would be). Also be aware that white box tests will break when we refactor. What to refactor in a database Refactoring databases doesn’t happen that often but when it does it can include a lot of stuff. Let us look at a few common cases. Adding or removing database schema objects Adding, removing or changing table columns in any way, adding constraints, keys, etc… All of these can be counted as internal changes not visible to the data consumer. But each of these carries a potential input/output behavior change. Dropping a column can result in views not working anymore or stored procedure logic crashing. Adding a unique constraint shows duplicated data that shouldn’t exist. Foreign keys break a truncate table command executed from an application that runs once a month. All these scenarios are very real and can happen. With the proper database abstraction layer fully covered with black box tests we can make sure something like that does not happen (hopefully at all). Changing physical structures Physical structures include heaps, indexes and partitions. We can pretty much add or remove those without changing the data returned by the database. But the performance can be affected. So here we use our performance tests. We do have them, right? Just by adding a single index we can achieve orders of magnitude performance improvement. Won’t that make users happy? But what if that index causes our write operations to crawl to a stop. again we have to test this. There are a lot of things to think about and have tests for. Without tests we can’t do successful refactoring! Fixing bad code We all have some bad code in our systems. We usually refer to that code as code smell as they violate good coding practices. Examples of such code smells are SQL injection, use of SELECT *, scalar UDFs or cursors, etc… Each of those is huge code smell and can result in major code changes. Take SELECT * from example. If we remove a column from a table the client using that SELECT * statement won’t have a clue about that until it runs. Then it will gracefully crash and burn. Not to mention the widely unknown SELECT * view refresh problem that Tomas LaRock (@SQLRockstar on Twitter) and Colin Stasiuk (@BenchmarkIT on Twitter) talk about in detail. Go read about it, it’s informative. Refactoring this includes replacing the * with column names and most likely change to application using the database. Breaking apart huge stored procedures Have you ever seen seen a stored procedure that was 2000 lines long? I have. It’s not pretty. It hurts the eyes and sucks the will to live the next 10 minutes. They are a maintenance nightmare and turn into things no one dares to touch. I’m willing to bet that 100% of time they don’t have a single test on them. Large stored procedures (and functions) are a clear sign that they contain business logic. General opinion on good database coding practices says that business logic has no business in the database. That’s the applications part. Refactoring such behemoths requires writing lots of edge case tests for the stored procedure input/output behavior and then start to refactor it. First we split the logic inside into smaller parts like new stored procedures and UDFs. Those then get called from the master stored procedure. Once we’ve successfully modularized the database code it’s best to transfer that logic into the applications consuming it. This only leaves the stored procedure with common data manipulation logic. Of course this isn’t always possible so having a plethora of performance and behavior unit tests is absolutely necessary to confirm we’ve actually improved the codebase in some way.   Refactoring is not a popular chore amongst developers or managers. The former don’t like fixing old code, the latter can’t see the financial benefit. Remember how we talked about being lousy at estimating future costs in the previous post? But there comes a time when it must be done. Hopefully I’ve given you some ideas how to get started. In the last post of the series we’ll take a look at the tools to use and an example of testing and refactoring.

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• Master Data

  - by david.butler(at)oracle.com

  Let's take a deeper look at what we mean when we talk about 'Master' data. In its most general sense, master data is data that exists in more than one operational application. These are the applications that automate business processes. These applications require significant amounts of data to function correctly.  This includes data about the objects that are involved in transactions, as well as the transaction data itself.  For example, when a customer buys a product, the transaction is managed by a sales application.  The objects of the transaction are the Customer and the Product.  The transactional data is the time, place, price, discount, payment methods, etc. used at the point of sale. Many thousands of transactional data attributes are needed within the application. These important data elements are local to the applications and have no bearing on other applications. Harmonization and synchronization across applications is not necessary. The Customer and Product objects of the transaction also have a large number of attributes. Customer for example, includes hierarchies, hierarchical and matrixed relationships, contacts, classifications, preferences, accounts, identifiers, profiles, and addresses galore for 'ship to', 'mail to'; 'service at'; etc. Dozens of attributes exist for individuals, hundreds for organizations, and thousands for products. This data has meaning beyond any particular application. It exists in many applications and drives the vital cross application enterprise business processes. These are the processes that define and differentiate the organization. At every decision point, information about the objects of the process determines the direction of the process flow. This is the nature of the data that exists in more than one application, and this is why we call it 'master data'. Let me elaborate. Parties Oracle has developed a party schema to model all participants in your daily business operations. It models people, organizations, groups, customers, contacts, employees, and suppliers. It models their accounts, locations, classifications, and preferences.  And most importantly, it models the vast array of hierarchical and matrixed relationships that exist between all the participants in your real world operations.  The model logically separates people and organizations from their relationships and accounts.  This separation creates flexibility unmatched in the industry and accounts for the fact that the Oracle schema for Customers, Suppliers, and Accounts is a true superset of the wide variety of commercial and homegrown customer models in existence. Sites Sites are places where business is conducted. They can be addresses, clusters such as retail malls, locations within a cluster, floors within a building, places where meters are located, rooms on floors, etc.  Fully understanding all attributes of a site is key to many business processes. Attributes such as 'noise abatement policy' at a point of delivery, or the size of an oven in a business kitchen drive day-to-day activities such as delivery schedules or food promotions. Typically this kind of data is siloed in departments and scattered across applications and spreadsheets.  This leads to conflicting information and poor operational efficiencies. Oracle's Global Single Schema can hold all site attributes in one place and enables a single version of authoritative site information across the enterprise. Products and Services The Oracle Global Single Schema also includes a number of entities that define the products and services a company creates and offers for sale. Key entities include Items organized into Catalogs and Price Lists. The Catalog structures provide for the ability to capture different views of a product such as engineering, manufacturing, and service which are based on a unified product model. As a result, designers, manufacturing engineers, purchasers and partners can work simultaneously on a common product definition. The Catalog schema allows for unlimited attributes, combines them into meaningful groups, and maps them to catalog categories to track these different types of information. The model also maps an unlimited number of functional structures for each item. For example, multiple Bills of Material (BOMs) can be constructed representing requirements BOM, features BOM, and packaging BOM for an item. The Catalog model also supports hierarchical information about each item and all standard Global Data Synchronization attributes. Business Processes Utilizing Linked Data Entities Each business entity codified into a centralized master data environment significantly improves the efficiency of the automated business processes that use the consolidated data.  When all the key business entities used by an organization's process are so consolidated, the advantages are multiplied.  The primary reason for business process breakdowns (i.e. data errors across application boundaries) is eliminated. All processes are positively impacted and business process automation is itself automated.  I like to use the "Call to Resolution" business process as an example to help illustrate this important point. It involves call center applications, service applications, RMA applications, transportation applications, inventory applications, etc. Customer, Site, Product and Supplier master data must all be correct and consistent across these applications.  What's more, the data relationships between customer and product, and product and suppliers must be right. This is the minimum quality needed to insure the business process flows without error. But that is not the end of the story. Critical master data attributes such as customer loyalty, profitability, credit worthiness, and propensity to buy can optimize the call center point of contact component of the process. Critical product information such as alternative parts or equivalent products can optimize the resolution selected by the process. A comprehensive understanding of the 'service at' location can help insure multiple trips are avoided in the process. Full supplier information on reliability, delivery delays, and potential alternates can prevent supplier exceptions and play a significant role in optimizing the process.  In other words, these master data attributes enable the optimization of the "Call to Resolution" enterprise business process. Master data supports and guides business process flows. Thus the phrase 'Master Data' is indeed appropriate. MDM is the software that houses, manages, and governs the master data that resides in all applications and controls the enterprise business processes. A complete master data solution takes a data model that holds fully attributed master data entities and their inter-relationships. Oracle has this model. Oracle, with its deep understanding of application data is the logical choice for managing all your master data within the enterprise whether or not your organization actually runs any Oracle Applications.

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• Agile Like Jazz

  - by Jeff Certain

  (I’ve been sitting on this for a week or so now, thinking that it needed to be tightened up a bit to make it less rambling. Since that’s clearly not going to happen, reader beware!) I had the privilege of spending around 90 minutes last night sitting and listening to Sonny Rollins play a concert at the Disney Center in LA. If you don’t know who Sonny Rollins is, I don’t know how to explain the experience; if you know who he is, I don’t need to. Suffice it to say that he has been recording professionally for over 50 years, and helped create an entire genre of music. A true master by any definition. One of the most intriguing aspects of a concert like this, however, is watching the master step aside and let the rest of the musicians play. Not just play their parts, but really play… letting them take over the spotlight, to strut their stuff, to soak up enthusiastic applause from the crowd. Maybe a lot of it has to do with the fact that Sonny Rollins has been doing this for more than a half-century. Maybe it has something to do with a kind of patience you learn when you’re on the far side of 80 – and the man can still blow a mean sax for 90 minutes without stopping! Maybe it has to do with the fact that he was out there for the love of the music and the love of the show, not because he had anything to prove to anyone and, I like to think, not for the money. Perhaps it had more to do with the fact that, when you’re at that level of mastery, the other musicians are going to be good. Really good. Whatever the reasons, there was a incredible freedom on that stage – the ability to improvise, for each musician to showcase their own specialization and skills, and them come back to the common theme, back to being on the same page, as it were. All this took place in the same venue that is home to the L.A. Phil. Somehow, I can’t ever see the same kind of free-wheeling improvisation happening in that context. And, since I’m a geek, I started thinking about agility. Rollins has put together a quintet that reflects his own particular style and past. No upright bass or piano for Rollins – drums, bongos, electric guitar and bass guitar along with his sax. It’s not about the mix of instruments. Other trios, quartets, and sextets use different mixes of instruments. New Orleans jazz tends towards trombones instead of sax; some prefer cornet or trumpet. But no matter what the choice of instruments, size matters. Team sizes are something I’ve been thinking about for a while. We’re on a quest to rethink how our teams are organized. They just feel too big, too unwieldy. In fact, they really don’t feel like teams at all. Most of the time, they feel more like collections or people who happen to report to the same manager. I attribute this to a couple factors. One is over-specialization; we have a tendency to have people work in silos. Although the teams are product-focused, within them our developers are both generalists and specialists. On the one hand, we expect them to be able to build an entire vertical slice of the application; on the other hand, each developer tends to be responsible for the vertical slice. As a result, developers often work on their own piece of the puzzle, in isolation. This sort of feels like working on a jigsaw in a group – each person taking a set of colors and piecing them together to reveal a portion of the overall picture. But what inevitably happens when you go to meld all those pieces together? Inevitably, you have some sections that are too big to move easily. These sections end up falling apart under their own weight as you try to move them. Not only that, but there are other challenges – figuring out where that section fits, and how to tie it into the rest of the puzzle. Often, this is when you find a few pieces need to be added – these pieces are “glue,” if you will. The other issue that arises is due to the overhead of maintaining communications in a team. My mother, who worked in IT for around 30 years, once told me that 20% per team member is a good rule of thumb for maintaining communication. While this is a rule of thumb, it seems to imply that any team over about 6 people is going to become less agile simple because of the communications burden. Teams of ten or twelve seem like they fall into the philharmonic organizational model. Complicated pieces of music requiring dozens of players to all be on the same page requires a much different model than the jazz quintet. There’s much less room for improvisation, originality or freedom. (There are probably orchestral musicians who will take exception to this characterization; I’m calling it like I see it from the cheap seats.) And, there’s one guy up front who is running the show, whose job is to keep all of those dozens of players on the same page, to facilitate communications. Somehow, the orchestral model doesn’t feel much like a self-organizing team, either. The first violin may be the best violinist in the orchestra, but they don’t get to perform free-wheeling solos. I’ve never heard of an orchestra getting together for a jam session. But I have heard of teams that organize their work based on the developers available, rather than organizing the developers based on the work required. I have heard of teams where desired functionality is deferred – or worse yet, schedules are missed – because one critical person doesn’t have any bandwidth available. I’ve heard of teams where people simply don’t have the big picture, because there is too much communication overhead for everyone to be aware of everything that is happening on a project. I once heard Paul Rayner say something to the effect of “you have a process that is perfectly designed to give you exactly the results you have.” Given a choice, I want a process that’s much more like jazz than orchestral music. I want a process that doesn’t burden me with lots of forms and checkboxes and stuff. Give me the simplest, most lightweight process that will work – and a smaller team of the best developers I can find. This seems like the kind of process that will get the kind of result I want to be part of.

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• The Faces in the Crowdsourcing

  - by Applications User Experience

  By Jeff Sauro, Principal Usability Engineer, Oracle Imagine having access to a global workforce of hundreds of thousands of people who can perform tasks or provide feedback on a design quickly and almost immediately. Distributing simple tasks not easily done by computers to the masses is called "crowdsourcing" and until recently was an interesting concept, but due to practical constraints wasn't used often. Enter Amazon.com. For five years, Amazon has hosted a service called Mechanical Turk, which provides an easy interface to the crowds. The service has almost half a million registered, global users performing a quarter of a million human intelligence tasks (HITs). HITs are submitted by individuals and companies in the U.S. and pay from $.01 for simple tasks (such as determining if a picture is offensive) to several dollars (for tasks like transcribing audio). What do we know about the people who toil away in this digital crowd? Can we rely on the work done in this anonymous marketplace? A rendering of the actual Mechanical Turk (from Wikipedia) Knowing who is behind Amazon's Mechanical Turk is fitting, considering the history of the actual Mechanical Turk. In the late 1800's, a mechanical chess-playing machine awed crowds as it beat master chess players in what was thought to be a mechanical miracle. It turned out that the creator, Wolfgang von Kempelen, had a small person (also a chess master) hiding inside the machine operating the arms to provide the illusion of automation. The field of human computer interaction (HCI) is quite familiar with gathering user input and incorporating it into all stages of the design process. It makes sense then that Mechanical Turk was a popular discussion topic at the recent Computer Human Interaction usability conference sponsored by the Association for Computing Machinery in Atlanta. It is already being used as a source for input on Web sites (for example, Feedbackarmy.com) and behavioral research studies. Two papers shed some light on the faces in this crowd. One paper tells us about the shifting demographics from mostly stay-at-home moms to young men in India. The second paper discusses the reliability and quality of work from the workers. Just who exactly would spend time doing tasks for pennies? In "Who are the crowdworkers?" University of California researchers Ross, Silberman, Zaldivar and Tomlinson conducted a survey of Mechanical Turk worker demographics and compared it to a similar survey done two years before. The initial survey reported workers consisting largely of young, well-educated women living in the U.S. with annual household incomes above $40,000. The more recent survey reveals a shift in demographics largely driven by an influx of workers from India. Indian workers went from 5% to over 30% of the crowd, and this block is largely male (two-thirds) with a higher average education than U.S. workers, and 64% report an annual income of less than $10,000 (keeping in mind $1 has a lot more purchasing power in India). This shifting demographic certainly has implications as language and culture can play critical roles in the outcome of HITs. Of course, the demographic data came from paying Turkers $.10 to fill out a survey, so there is some question about both a self-selection bias (characteristics which cause Turks to take this survey may be unrepresentative of the larger population), not to mention whether we can really trust the data we get from the crowd. Crowds can perform tasks or provide feedback on a design quickly and almost immediately for usability testing. (Photo attributed to victoriapeckham Flikr While having immediate access to a global workforce is nice, one major problem with Mechanical Turk is the incentive structure. Individuals and companies that deploy HITs want quality responses for a low price. Workers, on the other hand, want to complete the task and get paid as quickly as possible, so that they can get on to the next task. Since many HITs on Mechanical Turk are surveys, how valid and reliable are these results? How do we know whether workers are just rushing through the multiple-choice responses haphazardly answering? In "Are your participants gaming the system?" researchers at Carnegie Mellon (Downs, Holbrook, Sheng and Cranor) set up an experiment to find out what percentage of their workers were just in it for the money. The authors set up a 30-minute HIT (one of the more lengthy ones for Mechanical Turk) and offered a very high $4 to those who qualified and $.20 to those who did not. As part of the HIT, workers were asked to read an email and respond to two questions that determined whether workers were likely rushing through the HIT and not answering conscientiously. One question was simple and took little effort, while the second question required a bit more work to find the answer. Workers were led to believe other factors than these two questions were the qualifying aspect of the HIT. Of the 2000 participants, roughly 1200 (or 61%) answered both questions correctly. Eighty-eight percent answered the easy question correctly, and 64% answered the difficult question correctly. In other words, about 12% of the crowd were gaming the system, not paying enough attention to the question or making careless errors. Up to about 40% won't put in more than a modest effort to get paid for a HIT. Young men and those that considered themselves in the financial industry tended to be the most likely to try to game the system. There wasn't a breakdown by country, but given the demographic information from the first article, we could infer that many of these young men come from India, which makes language and other cultural differences a factor. These articles raise questions about the role of crowdsourcing as a means for getting quick user input at low cost. While compensating users for their time is nothing new, the incentive structure and anonymity of Mechanical Turk raises some interesting questions. How complex of a task can we ask of the crowd, and how much should these workers be paid? Can we rely on the information we get from these professional users, and if so, how can we best incorporate it into designing more usable products? Traditional usability testing will still play a central role in enterprise software. Crowdsourcing doesn't replace testing; instead, it makes certain parts of gathering user feedback easier. One can turn to the crowd for simple tasks that don't require specialized skills and get a lot of data fast. As more studies are conducted on Mechanical Turk, I suspect we will see crowdsourcing playing an increasing role in human computer interaction and enterprise computing. References: Downs, J. S., Holbrook, M. B., Sheng, S., and Cranor, L. F. 2010. Are your participants gaming the system?: screening mechanical turk workers. In Proceedings of the 28th international Conference on Human Factors in Computing Systems (Atlanta, Georgia, USA, April 10 - 15, 2010). CHI '10. ACM, New York, NY, 2399-2402. Link: http://doi.acm.org/10.1145/1753326.1753688 Ross, J., Irani, L., Silberman, M. S., Zaldivar, A., and Tomlinson, B. 2010. Who are the crowdworkers?: shifting demographics in mechanical turk. In Proceedings of the 28th of the international Conference Extended Abstracts on Human Factors in Computing Systems (Atlanta, Georgia, USA, April 10 - 15, 2010). CHI EA '10. ACM, New York, NY, 2863-2872. Link: http://doi.acm.org/10.1145/1753846.1753873

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• Elegance, thy Name is jQuery

  - by SGWellens

  So, I'm browsing though some questions over on the Stack Overflow website and I found a good jQuery question just a few minutes old. Here is a link to it. It was a tough question; I knew that by answering it, I could learn new stuff and reinforce what I already knew: Reading is good, doing is better. Maybe I could help someone in the process too. I cut and pasted the HTML from the question into my Visual Studio IDE and went back to Stack Overflow to reread the question. Dang, someone had already answered it! And it was a great answer. I never even had a chance to start analyzing the issue. Now I know what a one-legged man feels like in an ass-kicking contest. Nevertheless, since the question and answer were so interesting, I decided to dissect them and learn as much as possible. The HTML consisted of some divs separated by h3 headings.  Note the elements are laid out sequentially with no programmatic grouping: <h3 class="heading">Heading 1</h3> <div>Content</div> <div>More content</div> <div>Even more content</div><h3 class="heading">Heading 2</h3> <div>some content</div> <div>some more content</div><h3 class="heading">Heading 3</h3> <div>other content</div></form></body>  The requirement was to wrap a div around each h3 heading and the subsequent divs grouping them into sections. Why? I don't know, I suppose if you screen-scrapped some HTML from another site, you might want to reformat it before displaying it on your own. Anyways… Here is the marvelously, succinct posted answer: $('.heading').each(function(){ $(this).nextUntil('.heading').andSelf().wrapAll('<div class="section">');}); I was familiar with all the parts except for nextUntil and andSelf. But, I'll analyze the whole answer for completeness. I'll do this by rewriting the posted answer in a different style and adding a boat-load of comments: function Test(){ // $Sections is a jQuery object and it will contain three elements var $Sections = $('.heading'); // use each to iterate over each of the three elements $Sections.each(function () { // $this is a jquery object containing the current element // being iterated var $this = $(this); // nextUntil gets the following sibling elements until it reaches // an element with the CSS class 'heading' // andSelf adds in the source element (this) to the collection $this = $this.nextUntil('.heading').andSelf(); // wrap the elements with a div $this.wrapAll('<div class="section" >'); });}  The code here doesn't look nearly as concise and elegant as the original answer. However, unless you and your staff are jQuery masters, during development it really helps to work through algorithms step by step. You can step through this code in the debugger and examine the jQuery objects to make sure one step is working before proceeding on to the next. It's much easier to debug and troubleshoot when each logical coding step is a separate line. Note: You may think the original code runs much faster than this version. However, the time difference is trivial: Not enough to worry about: Less than 1 millisecond (tested in IE and FF). Note: You may want to jam everything into one line because it results in less traffic being sent to the client. That is true. However, most Internet servers now compress HTML and JavaScript by stripping out comments and white space (go to Bing or Google and view the source). This feature should be enabled on your server: Let the server compress your code, you don't need to do it. Free Career Advice: Creating maintainable code is Job One—Maximum Priority—The Prime Directive. If you find yourself suddenly transferred to customer support, it may be that the code you are writing is not as readable as it could be and not as readable as it should be. Moving on… I created a CSS class to see the results: .section{ background-color: yellow; border: 2px solid black; margin: 5px;} Here is the rendered output before:   …and after the jQuery code runs.   Pretty Cool! But, while playing with this code, the logic of nextUntil began to bother me: What happens in the last section? What stops elements from being collected since there are no more elements with the .heading class? The answer is nothing.  In this case it stopped because it was at the end of the page.  But what if there were additional HTML elements? I added an anchor tag and another div to the HTML: <h3 class="heading">Heading 1</h3> <div>Content</div> <div>More content</div> <div>Even more content</div><h3 class="heading">Heading 2</h3> <div>some content</div> <div>some more content</div><h3 class="heading">Heading 3</h3> <div>other content</div><a>this is a link</a><div>unrelated div</div> </form></body> The code as-is will include both the anchor and the unrelated div. This isn't what we want.   My first attempt to correct this used the filter parameter of the nextUntil function: nextUntil('.heading', 'div')  This will only collect div elements. But it merely skipped the anchor tag and it still collected the unrelated div:   The problem is we need a way to tell the nextUntil function when to stop. CSS selectors to the rescue: nextUntil('.heading, a')  This tells nextUntil to stop collecting sibling elements when it gets to an element with a .heading class OR when it gets to an anchor tag. In this case it solved the problem. FYI: The comma operator in a CSS selector allows multiple criteria.   Bingo! One final note, we could have broken the code down even more: We could have replaced the andSelf function here: $this = $this.nextUntil('.heading, a').andSelf(); With this: // get all the following siblings and then add the current item$this = $this.nextUntil('.heading, a');$this.add(this);  But in this case, the andSelf function reads real nice. In my opinion. Here's a link to a jsFiddle if you want to play with it. I hope someone finds this useful Steve Wellens CodeProject

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• Superclass Sensitive Actions

  - by Geertjan

  I've created a small piece of functionality that enables you to create actions for Java classes in the IDE. When the user right-clicks on a Java class, they will see one or more actions depending on the superclass of the selected class. To explain this visually, here I have "BlaTopComponent.java". I right-click on its node in the Projects window and I see "This is a TopComponent": Indeed, when you look at the source code of "BlaTopComponent.java", you'll see that it implements the TopComponent class. Next, in the screenshot below, you see that I have right-click a different class. In this case, there's an action available because the selected class implements the ActionListener class. Then, take a look at this one. Here both TopComponent and ActionListener are superclasses of the current class, hence both the actions are available to be invoked: Finally, here's a class that subclasses neither TopComponent nor ActionListener, hence neither of the actions that I created for doing something that relates to TopComponents or ActionListeners is available, since those actions are irrelevant in this context: How does this work? Well, it's a combination of my blog entries "Generic Node Popup Registration Solution" and "Showing an Action on a TopComponent Node". The cool part is that the definition of the two actions that you see above is remarkably trivial: import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JOptionPane; import org.openide.loaders.DataObject; import org.openide.util.Utilities; public class TopComponentSensitiveAction implements ActionListener { private final DataObject context; public TopComponentSensitiveAction() { context = Utilities.actionsGlobalContext().lookup(DataObject.class); } @Override public void actionPerformed(ActionEvent ev) { //Do something with the context: JOptionPane.showMessageDialog(null, "TopComponent: " + context.getNodeDelegate().getDisplayName()); } } The above is the action that will be available if you right-click a Java class that extends TopComponent. This, in turn, is the action that will be available if you right-click a Java class that implements ActionListener: import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JOptionPane; import org.openide.loaders.DataObject; import org.openide.util.Utilities; public class ActionListenerSensitiveAction implements ActionListener { private final DataObject context; public ActionListenerSensitiveAction() { context = Utilities.actionsGlobalContext().lookup(DataObject.class); } @Override public void actionPerformed(ActionEvent ev) { //Do something with the context: JOptionPane.showMessageDialog(null, "ActionListener: " + context.getNodeDelegate().getDisplayName()); } } Indeed, the classes, at this stage are the same. But, depending on what I want to do with TopComponents or ActionListeners, I now have a starting point, which includes access to the DataObject, from where I can get down into the source code, as shown here. This is how the two ActionListeners that you see defined above are registered in the layer, which could ultimately be done via annotations on the ActionListeners, of course: <folder name="Actions"> <folder name="Tools"> <file name="org-netbeans-sbas-impl-TopComponentSensitiveAction.instance"> <attr stringvalue="This is a TopComponent" name="displayName"/> <attr name="instanceCreate" methodvalue="org.netbeans.sbas.SuperclassSensitiveAction.create"/> <attr name="type" stringvalue="org.openide.windows.TopComponent"/> <attr name="delegate" newvalue="org.netbeans.sbas.impl.TopComponentSensitiveAction"/> </file> <file name="org-netbeans-sbas-impl-ActionListenerSensitiveAction.instance"> <attr stringvalue="This is an ActionListener" name="displayName"/> <attr name="instanceCreate" methodvalue="org.netbeans.sbas.SuperclassSensitiveAction.create"/> <attr name="type" stringvalue="java.awt.event.ActionListener"/> <attr name="delegate" newvalue="org.netbeans.sbas.impl.ActionListenerSensitiveAction"/> </file> </folder> </folder> <folder name="Loaders"> <folder name="text"> <folder name="x-java"> <folder name="Actions"> <file name="org-netbeans-sbas-impl-TopComponentSensitiveAction.shadow"> <attr name="originalFile" stringvalue="Actions/Tools/org-netbeans-sbas-impl-TopComponentSensitiveAction.instance"/> <attr intvalue="150" name="position"/> </file> <file name="org-netbeans-sbas-impl-ActionListenerSensitiveAction.shadow"> <attr name="originalFile" stringvalue="Actions/Tools/org-netbeans-sbas-impl-ActionListenerSensitiveAction.instance"/> <attr intvalue="160" name="position"/> </file> </folder> </folder> </folder> </folder> The most important parts of the layer registration are the lines that are highlighted above. Those lines connect the layer to the generic action that delegates back to the action listeners defined above, as follows: public final class SuperclassSensitiveAction extends AbstractAction implements ContextAwareAction { private final Map map; //This method is called from the layer, via "instanceCreate", //magically receiving a map, which contains all the attributes //that are defined in the layer for the file: static SuperclassSensitiveAction create(Map map) { return new SuperclassSensitiveAction(Utilities.actionsGlobalContext(), map); } public SuperclassSensitiveAction(Lookup context, Map m) { super(m.get("displayName").toString()); this.map = m; String superclass = m.get("type").toString(); //Enable the menu item only if //we're dealing with a class of type superclass: JavaSource javaSource = JavaSource.forFileObject( context.lookup(DataObject.class).getPrimaryFile()); try { javaSource.runUserActionTask(new ScanTask(this, superclass), true); } catch (IOException ex) { Exceptions.printStackTrace(ex); } //Hide the menu item if it isn't enabled: putValue(DynamicMenuContent.HIDE_WHEN_DISABLED, true); } @Override public void actionPerformed(ActionEvent ev) { ActionListener delegatedAction = (ActionListener)map.get("delegate"); delegatedAction.actionPerformed(ev); } @Override public Action createContextAwareInstance(Lookup actionContext) { return new SuperclassSensitiveAction(actionContext, map); } private class ScanTask implements Task<CompilationController> { private SuperclassSensitiveAction action = null; private String superclass; private ScanTask(SuperclassSensitiveAction action, String superclass) { this.action = action; this.superclass = superclass; } @Override public void run(final CompilationController info) throws Exception { info.toPhase(Phase.ELEMENTS_RESOLVED); new EnableIfGivenSuperclassMatches(info, action, superclass).scan( info.getCompilationUnit(), null); } } private static class EnableIfGivenSuperclassMatches extends TreePathScanner<Void, Void> { private CompilationInfo info; private final AbstractAction action; private final String superclassName; public EnableIfGivenSuperclassMatches(CompilationInfo info, AbstractAction action, String superclassName) { this.info = info; this.action = action; this.superclassName = superclassName; } @Override public Void visitClass(ClassTree t, Void v) { Element el = info.getTrees().getElement(getCurrentPath()); if (el != null) { TypeElement te = (TypeElement) el; List<? extends TypeMirror> interfaces = te.getInterfaces(); if (te.getSuperclass().toString().equals(superclassName)) { action.setEnabled(true); } else { action.setEnabled(false); } for (TypeMirror typeMirror : interfaces) { if (typeMirror.toString().equals(superclassName)){ action.setEnabled(true); } } } return null; } } } This is a pretty cool solution and, as you can see, very generic. Create a new ActionListener, register it in the layer so that it maps to the generic class above, and make sure to set the type attribute, which defines the superclass to which the action should be sensitive.

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• 10 tape technology features that make you go hmm.

  - by Karoly Vegh

  A week ago an Oracle/StorageTek Tape Specialist, Christian Vanden Balck, visited Vienna, and agreed to visit customers to do techtalks and update them about the technology boom going around tape. I had the privilege to attend some of his sessions and noted the information and features that took the customers by surprise and made them think. Allow me to share the top 10: I. StorageTek as a brand: StorageTek is one of he strongest names in the Tape field. The brand itself was valued so much by customers that even after Sun Microsystems acquiring StorageTek and the Oracle acquiring Sun the brand lives on with all the Oracle tapelibraries are officially branded StorageTek.See http://www.oracle.com/us/products/servers-storage/storage/tape-storage/overview/index.html II. Disk information density limitations: Disk technology struggles with information density. You haven't seen the disk sizes exploding lately, have you? That's partly because there are physical limits on a disk platter. The size is given, the number of platters is limited, they just can't grow, and are running out of physical area to write to. Now, in a T10000C tape cartridge we have over 1000m long tape. There you go, you have got your physical space and don't need to stuff all that data crammed together. You can write in a reliable pattern, and have space to grow too. III. Oracle has a market share of 62% worldwide in recording head manufacturing. That's right. If you are running LTO drives, with a good chance you rely on StorageTek production. That's two out of three LTO recording heads produced worldwide.  IV. You can store 1 Exabyte data in a single tape library. Yes, an Exabyte. That is 1000 Petabytes. Or, a million Terabytes. A thousand million GigaBytes. You can store that in a stacked StorageTek SL8500 tapelibrary. In one SL8500 you can put 10.000 T10000C cartridges, that store 10TB data (compressed). You can stack 10 of these SL8500s together. Boom. 1000.000 TB.(n.b.: stacking means interconnecting the libraries. Yes, cartridges are moved between the stacked libraries automatically.)  V. EMC: 'Tape doesn't suck after all. We moved on.': Do you remember the infamous 'Tape sucks, move on' Datadomain slogan? Of course they had to put it that way, having only had disk products. But here's a fun fact: on the EMCWorld 2012 there was a major presence of a Tape-tech company - EMC, in a sudden burst of sanity is embracing tape again. VI. The miraculous T10000C: Oracle StorageTek has developed an enterprise-grade tapedrive and cartridge, the T10000C. With awesome numbers: The Cartridge: Native 5TB capacity, 10TB with compression Over a kilometer long tape within the cartridge. And it's locked when unmounted, no rattling of your data.  Replaced the metalparticles datalayer with BaFe (bariumferrite) - metalparticles lose around 7% of magnetism within 30 days. BaFe does not. Yes we employ solid-state physicists doing R&D on demagnetisation in our labs. Can be partitioned, storage tiering within the cartridge!  The Drive: 2GB Cache Encryption implemented in HW - no performance hit 252 MB/s native sustained data rate, beats disk technology by far. Not to mention peak throughput.  Leading the tape while never touching the data side of it, protecting your data physically too Data integritiy checking (CRC recalculation) on tape within the drive without having to read it back to the server reordering data from tape-order, delivering it back in application-order  writing 32 tracks at once, reading them back for CRC check at once VII. You only use 20% of your data on a regular basis. The rest 80% is just lying around for years. On continuously spinning disks. Doubly consuming energy (power+cooling), blocking diskstorage capacity. There is a solution called SAM (Storage Archive Manager) that provides you a filesystem unifying disk and tape, moving data on-demand and for clients transparently between the different storage tiers. You can share these filesystems with NFS or CIFS for clients, and enjoy the low TCO of tape. Tapes don't spin. They sit quietly in their slots, storing 10TB data, using no energy, producing no heat, automounted when a client accesses their data.See: http://www.oracle.com/us/products/servers-storage/storage/storage-software/storage-archive-manager/overview/index.html VIII. HW supported for three decades: Did you know that the original PowderHorn library was released in '87 and has been only discontinued in 2010? That is over two decades of supported operation. Tape libraries are - just like the data carrying on tapecartridges - built for longevity. Oh, and the T10000C cartridge has 30-year archival life for long-term retention.  IX. Tape is easy to manage: Have you heard of Tape Storage Analytics? It is a central graphical tool to summarize, monitor, analyze dataflow, health and performance of drives and libraries, see: http://www.oracle.com/us/products/servers-storage/storage/tape-storage/tape-analytics/overview/index.html X. The next generation: The T10000B drives were able to reuse the T10000A cartridges and write on them even more data. On the same cartridges. We call this investment protection, and this is very important for Oracle for the future too. We usually support two generations of cartridges together. The current drive is a T10000C. (...I know I promised to enlist 10, but I got still two more I really want to mention. Allow me to work around the problem: ) X++. The TallBots, the robots moving around the cartridges in the StorageTek library from tapeslots to the drives are cableless. Cables, belts, chains running to moving parts in a library cause maintenance downtimes. So StorageTek eliminated them. The TallBots get power, commands, even firmwareupgrades through the rails they are running on. Also, the TallBots don't just hook'n'pull the tapes out of their slots, they actually grip'n'lift them out. No friction, no scratches, no zillion little plastic particles floating around in the library, in the drives, on your data. (X++)++: Tape beats SSDs and Disks. In terms of throughput (252 MB/s), in terms of TCO: disks cause around 290x more power and cooling, in terms of capacity: 10TB on a single media and soon more.  So... do you need to store large amounts of data? Are you legally bound to archive it for dozens of years? Would you benefit from automatic storage tiering? Have you got large mediachunks to be streamed at times? Have you got power and cooling issues in the growing datacenters? Do you find EMC's 180° turn of tape attitude interesting, but appreciate it at the same time? With all that, you aren't alone. The most data on this planet is stored on tape. Tape is coming. Big time.

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• RIF PRD: Presentation syntax issues

  - by Charles Young

  Over Christmas I got to play a bit with the W3C RIF PRD and came across a few issues which I thought I would record for posterity. Specifically, I was working on a grammar for the presentation syntax using a GLR grammar parser tool (I was using the current CTP of ‘M’ (MGrammer) and Intellipad – I do so hope the MS guys don’t kill off M and Intellipad now they have dropped the other parts of SQL Server Modelling). I realise that the presentation syntax is non-normative and that any issues with it do not therefore compromise the standard. However, presentation syntax is useful in its own right, and it would be great to iron out any issues in a future revision of the standard. The main issues are actually not to do with the grammar at all, but rather with the ‘running example’ in the RIF PRD recommendation. I started with the code provided in Example 9.1. There are several discrepancies when compared with the EBNF rules documented in the standard. Broadly the problems can be categorised as follows: ·      Parenthesis mismatch – the wrong number of parentheses are used in various places. For example, in GoldRule, the RHS of the rule (the ‘Then’) is nested in the LHS (‘the If’). In NewCustomerAndWidgetRule, the RHS is orphaned from the LHS. Together with additional incorrect parenthesis, this leads to orphanage of UnknownStatusRule from the entire Document. ·      Invalid use of parenthesis in ‘Forall’ constructs. Parenthesis should not be used to enclose formulae. Removal of the invalid parenthesis gave me a feeling of inconsistency when comparing formulae in Forall to formulae in If. The use of parenthesis is not actually inconsistent in these two context, but in an If construct it ‘feels’ as if you are enclosing formulae in parenthesis in a LISP-like fashion. In reality, the parenthesis is simply being used to group subordinate syntax elements. The fact that an If construct can contain only a single formula as an immediate child adds to this feeling of inconsistency. ·      Invalid representation of compact URIs (CURIEs) in the context of Frame productions. In several places the URIs are not qualified with a namespace prefix (‘ex1:’). This conflicts with the definition of CURIEs in the RIF Datatypes and Built-Ins 1.0 document. Here are the productions: CURIE          ::= PNAME_LN                  | PNAME_NS PNAME_LN       ::= PNAME_NS PN_LOCAL PNAME_NS       ::= PN_PREFIX? ':' PN_LOCAL       ::= ( PN_CHARS_U | [0-9] ) ((PN_CHARS|'.')* PN_CHARS)? PN_CHARS       ::= PN_CHARS_U                  | '-' | [0-9] | #x00B7                  | [#x0300-#x036F] | [#x203F-#x2040] PN_CHARS_U     ::= PN_CHARS_BASE                  | '_' PN_CHARS_BASE ::= [A-Z] | [a-z] | [#x00C0-#x00D6] | [#x00D8-#x00F6]                  | [#x00F8-#x02FF] | [#x0370-#x037D] | [#x037F-#x1FFF]                  | [#x200C-#x200D] | [#x2070-#x218F] | [#x2C00-#x2FEF]                  | [#x3001-#xD7FF] | [#xF900-#xFDCF] | [#xFDF0-#xFFFD]                  | [#x10000-#xEFFFF] PN_PREFIX      ::= PN_CHARS_BASE ((PN_CHARS|'.')* PN_CHARS)? The more I look at CURIEs, the more my head hurts! The RIF specification allows prefixes and colons without local names, which surprised me. However, the CURIE Syntax 1.0 working group note specifically states that this form is supported…and then promptly provides a syntactic definition that seems to preclude it! However, on (much) deeper inspection, it appears that ‘ex1:’ (for example) is allowed, but would really represent a ‘fragment’ of the ‘reference’, rather than a prefix! Ouch! This is so completely ambiguous that it surely calls into question the whole CURIE specification.   In any case, RIF does not allow local names without a prefix. ·      Missing ‘External’ specifiers for built-in functions and predicates.  The EBNF specification enforces this for terms within frames, but does not appear to enforce (what I believe is) the correct use of External on built-in predicates. In any case, the running example only specifies ‘External’ once on the predicate in UnknownStatusRule. External() is required in several other places. ·      The List used on the LHS of UnknownStatusRule is comma-delimited. This is not supported by the EBNF definition. Similarly, the argument list of pred:list-contains is illegally comma-delimited. ·      Unnecessary use of conjunction around a single formula in DiscountRule. This is strictly legal in the EBNF, but redundant.   All the above issues concern the presentation syntax used in the running example. There are a few minor issues with the grammar itself. Note that Michael Kiefer stated in his paper “Rule Interchange Format: The Framework” that: “The presentation syntax of RIF … is an abstract syntax and, as such, it omits certain details that might be important for unambiguous parsing.” ·      The grammar cannot differentiate unambiguously between strategies and priorities on groups. A processor is forced to resolve this by detecting the use of IRIs and integers. This could easily be fixed in the grammar.   ·      The grammar cannot unambiguously parse the ‘->’ operator in frames. Specifically, ‘-’ characters are allowed in PN_LOCAL names and hence a parser cannot determine if ‘status->’ is (‘status’ ‘->’) or (‘status-’ ‘>’).   One way to fix this is to amend the PN_LOCAL production as follows: PN_LOCAL ::= ( PN_CHARS_U | [0-9] ) ((PN_CHARS|'.')* ((PN_CHARS)-('-')))? However, unilaterally changing the definition of this production, which is defined in the SPARQL Query Language for RDF specification, makes me uncomfortable. ·      I assume that the presentation syntax is case-sensitive. I couldn’t find this stated anywhere in the documentation, but function/predicate names do appear to be documented as being case-sensitive. ·      The EBNF does not specify whitespace handling. A couple of productions (RULE and ACTION_BLOCK) are crafted to enforce the use of whitespace. This is not necessary. It seems inconsistent with the rest of the specification and can cause parsing issues. In addition, the Const production exhibits whitespaces issues. The intention may have been to disallow the use of whitespace around ‘^^’, but any direct implementation of the EBNF will probably allow whitespace between ‘^^’ and the SYMSPACE. Of course, I am being a little nit-picking about all this. On the whole, the EBNF translated very smoothly and directly to ‘M’ (MGrammar) and proved to be fairly complete. I have encountered far worse issues when translating other EBNF specifications into usable grammars.   I can’t imagine there would be any difficulty in implementing the same grammar in Antlr, COCO/R, gppg, XText, Bison, etc. A general observation, which repeats a point made above, is that the use of parenthesis in the presentation syntax can feel inconsistent and un-intuitive.   It isn’t actually inconsistent, but I think the presentation syntax could be improved by adopting braces, rather than parenthesis, to delimit subordinate syntax elements in a similar way to so many programming languages. The familiarity of braces would communicate the structure of the syntax more clearly to people like me.  If braces were adopted, parentheses could be retained around ‘var (frame | ‘new()’) constructs in action blocks. This use of parenthesis feels very LISP-like, and I think that this is my issue. It’s as if the presentation syntax represents the deformed love-child of LISP and C. In some places (specifically, action blocks), parenthesis is used in a LISP-like fashion. In other places it is used like braces in C. I find this quite confusing. Here is a corrected version of the running example (Example 9.1) in compliant presentation syntax: Document(    Prefix( ex1 <http://example.com/2009/prd2> )    (* ex1:CheckoutRuleset *)  Group rif:forwardChaining (     (* ex1:GoldRule *)    Group 10 (      Forall ?customer such that And(?customer # ex1:Customer                                     ?customer[ex1:status->"Silver"])        (Forall ?shoppingCart such that ?customer[ex1:shoppingCart->?shoppingCart]           (If Exists ?value (And(?shoppingCart[ex1:value->?value]                                  External(pred:numeric-greater-than-or-equal(?value 2000))))            Then Do(Modify(?customer[ex1:status->"Gold"])))))      (* ex1:DiscountRule *)    Group (      Forall ?customer such that ?customer # ex1:Customer        (If Or( ?customer[ex1:status->"Silver"]                ?customer[ex1:status->"Gold"])         Then Do ((?s ?customer[ex1:shoppingCart-> ?s])                  (?v ?s[ex1:value->?v])                  Modify(?s [ex1:value->External(func:numeric-multiply (?v 0.95))]))))      (* ex1:NewCustomerAndWidgetRule *)    Group (      Forall ?customer such that And(?customer # ex1:Customer                                     ?customer[ex1:status->"New"] )        (If Exists ?shoppingCart ?item                   (And(?customer[ex1:shoppingCart->?shoppingCart]                        ?shoppingCart[ex1:containsItem->?item]                        ?item # ex1:Widget ) )         Then Do( (?s ?customer[ex1:shoppingCart->?s])                  (?val ?s[ex1:value->?val])                  (?voucher ?customer[ex1:voucher->?voucher])                  Retract(?customer[ex1:voucher->?voucher])                  Retract(?voucher)                  Modify(?s[ex1:value->External(func:numeric-multiply(?val 0.90))]))))      (* ex1:UnknownStatusRule *)    Group (      Forall ?customer such that ?customer # ex1:Customer        (If Not(Exists ?status                       (And(?customer[ex1:status->?status]                            External(pred:list-contains(List("New" "Bronze" "Silver" "Gold") ?status)) )))         Then Do( Execute(act:print(External(func:concat("New customer: " ?customer))))                  Assert(?customer[ex1:status->"New"]))))  ) )   I hope that helps someone out there :-)

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• 5 Best Practices - Laying the Foundation for WebCenter Projects

  - by Kellsey Ruppel

  Today’s guest post comes from Oracle WebCenter expert John Brunswick. John specializes in enterprise portal and content management solutions and actively contributes to the enterprise software business community and has authored a series of articles about optimal business involvement in portal, business process management and SOA development, examining ways of helping organizations move away from monolithic application development. We’re happy to have John join us today! Maximizing success with Oracle WebCenter portal requires a strategic understanding of Oracle WebCenter capabilities.  The following best practices enable the creation of portal solutions with minimal resource overhead, while offering the greatest flexibility for progressive elaboration. They are inherently project agnostic, enabling a strong foundation for future growth and an expedient return on your investment in the platform.  If you are able to embrace even only a few of these practices, you will materially improve your deployment capability with WebCenter. 1. Segment Duties Around 3Cs - Content, Collaboration and Contextual Data "Agility" is one of the most common business benefits touted by modern web platforms.  It sounds good - who doesn't want to be Agile, right?  How exactly IT organizations go about supplying agility to their business counterparts often lacks definition - hamstrung by ambiguity. Ultimately, businesses want to benefit from reduced development time to deliver a solution to a particular constituent, which is augmented by as much self-service as possible to develop and manage the solution directly. All done in the absence of direct IT involvement. With Oracle WebCenter's depth in the areas of content management, pallet of native collaborative services, enterprise mashup capability and delegated administration, it is very possible to execute on this business vision at a technical level. To realize the benefits of the platform depth we can think of Oracle WebCenter's segmentation of duties along the lines of the 3 Cs - Content, Collaboration and Contextual Data.  All three of which can have their foundations developed by IT, then provisioned to the business on a per role basis. Content – Oracle WebCenter benefits from an extremely mature content repository.  Work flow, audit, notification, office integration and conversion capabilities for documents (HTML & PDF) make this a haven for business users to take control of content within external and internal portals, custom applications and web sites.  When deploying WebCenter portal take time to think of areas in which IT can provide the "harness" for content to reside, then allow the business to manage any content items within the site, using the content foundation to ensure compliance with business rules and process.  This frees IT to work on more mission critical challenges and allows the business to respond in short order to emerging market needs. Collaboration – Native collaborative services and WebCenter spaces are a perfect match for business users who are looking to enable document sharing, discussions and social networking.  The ability to deploy the services is granular and on the basis of roles scoped to given areas of the system - much like the first C “content”.  This enables business analysts to design the roles required and IT to provision with peace of mind that users leveraging the collaborative services are only able to do so in explicitly designated areas of a site. Bottom line - business will not need to wait for IT, but cannot go outside of the scope that has been defined based on their roles. Contextual Data – Collaborative capabilities are most powerful when included within the context of business data.  The ability to supply business users with decision shaping data that they can include in various parts of a portal or portals, just as they would with content items, is one of the most powerful aspects of Oracle WebCenter.  Imagine a discussion about new store selection for a retail chain that re-purposes existing information from business intelligence services about various potential locations and or custom backend systems - presenting it directly in the context of the discussion.  If there are some data sources that are preexisting in your enterprise take a look at how they can be made into discrete offerings within the portal, then scoped to given business user roles for inclusion within collaborative activities. 2. Think Generically, Execute Specifically Constructs.  Anyone who has spent much time around me knows that I am obsessed with this word.  Why? Because Constructs offer immense power - more than APIs, Web Services or other technical capability. Constructs offer organizations the ability to leverage a platform's native characteristics to offer substantial business functionality - without writing code.  This concept becomes more powerful with the additional understanding of the concepts from the platform that an organization learns over time.  Let's take a look at an example of where an Oracle WebCenter construct can substantially reduce the time to get a subscription-based site out the door and into the hands of the end consumer. Imagine a site that allows members to subscribe to specific disciplines to access information and application data around that various discipline.  A space is a collection of secured pages within Oracle WebCenter.  Spaces are not only secured, but also default content stored within it to be scoped automatically to that space. Taking this a step further, Oracle WebCenter’s Activity Stream surfaces events, discussions and other activities that are scoped to the given user on the basis of their space affiliations.  In order to have a portal that would allow users to "subscribe" to information around various disciplines - spaces could be used out of the box to achieve this capability and without using any APIs or low level technical work to achieve this. 3. Make Governance Work for You Imagine driving down the street without the painted lines on the road.  The rules of the road are so ingrained in our minds, we often do not think about the process, but seemingly mundane lane markers are critical enablers. Lane markers allow us to travel at speeds that would be impossible if not for the agreed upon direction of flow. Additionally and more importantly, it allows people to act autonomously - going where they please at any given time. The return on the investment for mobility is high enough for people to buy into globally agreed up governance processes. In Oracle WebCenter we can use similar enablers to lane markers.  Our goal should be to enable the flow of information and provide end users with the ability to arrive at business solutions as needed, not on the basis of cumbersome processes that cannot meet the business needs in a timely fashion. How do we do this? Just as with "Segmentation of Duties" Oracle WebCenter technologies offer the opportunity to compartmentalize various business initiatives from each other within the system due to constructs and security that are available to use within the platform. For instance, when a WebCenter space is created, any content added within that space by default will be secured to that particular space and inherits meta data that is associated with a folder created for the space. Oracle WebCenter content uses meta data to support a broad range of rich ECM functionality and can automatically impart retention, workflow and other policies automatically on the basis of what has been defaulted for that space. Depending on your business needs, this paradigm will also extend to sub sections of a space, offering some interesting possibilities to enable automated management around content. An example may be press releases within a particular area of an extranet that require a five year retention period and need to the reviewed by marketing and legal before release.  The underlying content system will transparently take care of this process on the basis of the above rules, enabling peace of mind over unstructured data - which could otherwise become overwhelming. 4. Make Your First Project Your Second Imagine if Michael Phelps was competing in a swimming championship, but told right before his race that he had to use a brand new stroke.  There is no doubt that Michael is an outstanding swimmer, but chances are that he would like to have some time to get acquainted with the new stroke. New technologies should not be treated any differently.  Before jumping into the deep end it helps to take time to get to know the new approach - even though you may have been swimming thousands of times before. To quickly get a handle on Oracle WebCenter capabilities it can be helpful to deploy a sandbox for the team to use to share project documents, discussions and announcements in an effort to help the actual deployment get under way, while increasing everyone’s knowledge of the platform and its functionality that may be helpful down the road. Oracle Technology Network has made a pre-configured virtual machine available for download that can be a great starting point for this exercise. 5. Get to Know the Community If you are reading this blog post you have most certainly faced a software decision or challenge that was solved on the basis of a small piece of missing critical information - which took substantial research to discover.  Chances were also good that somewhere, someone had already come across this information and would have been excited to share it. There is no denying the power of passionate, connected users, sharing key tips around technology.  The Oracle WebCenter brand has a rich heritage that includes industry-leading technology and practitioners.  With the new Oracle WebCenter brand, opportunities to connect with these experts has become easier. Oracle WebCenter Blog Oracle Social Enterprise LinkedIn WebCenter Group Oracle WebCenter Twitter Oracle WebCenter Facebook Oracle User Groups Additionally, there are various Oracle WebCenter related blogs by an excellent grouping of services partners.

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• Building an Infrastructure Cloud with Oracle VM for x86 + Enterprise Manager 12c

  - by Richard Rotter

  Cloud Computing? Everyone is talking about Cloud these days. Everyone is explaining how the cloud will help you to bring your service up and running very fast, secure and with little effort. You can find these kinds of presentations at almost every event around the globe. But what is really behind all this stuff? Is it really so simple? And the answer is: Yes it is! With the Oracle SW Stack it is! In this post, I will try to bring this down to earth, demonstrating how easy it could be to build a cloud infrastructure with Oracle's solution for cloud computing.But let me cover some basics first: How fast can you build a cloud?How elastic is your cloud so you can provide new services on demand? How much effort does it take to monitor and operate your Cloud Infrastructure in order to meet your SLAs?How easy is it to chargeback for your services provided? These are the critical success factors of Cloud Computing. And Oracle has an answer to all those questions. By using Oracle VM for X86 in combination with Enterprise Manager 12c you can build and control your cloud environment very fast and easy. What are the fundamental building blocks for your cloud? Oracle Cloud Building Blocks #1 Hardware Surprise, surprise. Even the cloud needs to run somewhere, hence you will need hardware. This HW normally consists of servers, storage and networking. But Oracles goes beyond that. There are Optimized Solutions available for your cloud infrastructure. This is a cookbook to build your HW cloud platform. For example, building your cloud infrastructure with blades and our network infrastructure will reduce complexity in your datacenter (Blades with switch network modules, splitter cables to reduce the amount of cables, TOR (Top Of the Rack) switches which are building the interface to your infrastructure environment. Reducing complexity even in the cabling will help you to manage your environment more efficient and with less risk. Of course, our engineered systems fit into the cloud perfectly too. Although they are considered as a PaaS themselves, having the database SW (for Exadata) and the application development environment (for Exalogic) already deployed on them, in general they are ideal systems to enable you building your own cloud and PaaS infrastructure. #2 Virtualization The next missing link in the cloud setup is virtualization. For me personally, it's one of the most hidden "secret", that oracle can provide you with a complete virtualization stack in terms of a hypervisor on both architectures: X86 and Sparc CPUs. There is Oracle VM for X86 and Oracle VM for Sparc available at no additional  license costs if your are running this virtualization stack on top of Oracle HW (and with Oracle Premier Support for HW). This completes the virtualization portfolio together with Solaris Zones introduced already with Solaris 10 a few years ago. Let me explain how Oracle VM for X86 works: Oracle VM for x86 consists of two main parts: - The Oracle VM Server: Oracle VM Server is installed on bare metal and it is the hypervisor which is able to run virtual machines. It has a very small footprint. The ISO-Image of Oracle VM Server is only 200MB large. It is very small but efficient. You can install a OVM-Server in less than 5 mins by booting the Server with the ISO-Image assigned and providing the necessary configuration parameters (like installing an Linux distribution). After the installation, the OVM-Server is ready to use. That's all. - The Oracle VM-Manager: OVM-Manager is the central management tool where you can control your OVM-Servers. OVM-Manager provides the graphical user interface, which is an Application Development Framework (ADF) application, with a familiar web-browser based interface, to manage Oracle VM Servers, virtual machines, and resources. The Oracle VM Manager has the following capabilities: Create virtual machines Create server pools Power on and off virtual machines Manage networks and storage Import virtual machines, ISO files, and templates Manage high availability of Oracle VM Servers, server pools, and virtual machines Perform live migration of virtual machines I want to highlight one of the goodies which you can use if you are running Oracle VM for X86: Preconfigured, downloadable Virtual Machine Templates form edelivery With these templates, you can download completely preconfigured Virtual Machines in your environment, boot them up, configure them at first time boot and use it. There are templates for almost all Oracle SW and Applications (like Fusion Middleware, Database, Siebel, etc.) available. #3) Cloud Management The management of your cloud infrastructure is key. This is a day-to-day job. Acquiring HW, installing a virtualization layer on top of it is done just at the beginning and if you want to expand your infrastructure. But managing your cloud, keeping it up and running, deploying new services, changing your chargeback model, etc, these are the daily jobs. These jobs must be simple, secure and easy to manage. The Enterprise Manager 12c Cloud provides this functionality from one management cockpit. Enterprise Manager 12c uses Oracle VM Manager to control OVM Serverpools. Once you registered your OVM-Managers in Enterprise Manager, then you are able to setup your cloud infrastructure and manage everything from Enterprise Manager. What you need to do in EM12c is: ">Register your OVM Manager in Enterprise ManagerAfter Registering your OVM Manager, all the functionality of Oracle VM for X86 is also available in Enterprise Manager. Enterprise Manager works as a "Manger" of the Manager. You can register as many OVM-Managers you want and control your complete virtualization environment Create Roles and Users for your Self Service Portal in Enterprise ManagerWith this step you allow users to logon on the Enterprise Manager Self Service Portal. Users can request Virtual Machines in this portal. Setup the Cloud InfrastructureSetup the Quotas for your self service users. How many VMs can they request? How much of your resources ( cpu, memory, storage, network, etc. etc.)? Which SW components (templates, assemblys) can your self service users request? In this step, you basically set up the complete cloud infrastructure. Setup ChargebackOnce your cloud is set up, you need to configure your chargeback mechanism. The Enterprise Manager collects the resources metrics, which are used in a very deep level. Almost all collected Metrics could be used in the chargeback module. You can define chargeback plans based on configurations (charge for the amount of cpu, memory, storage is assigned to a machine, or for a specific OS which is installed) or chargeback on resource consumption (% of cpu used, storage used, etc). Or you can also define a combination of configuration and consumption chargeback plans. The chargeback module is very flexible. Here is a overview of the workflow how to handle infrastructure cloud in EM: Summary As you can see, setting up an Infrastructure Cloud Service with Oracle VM for X86 and Enterprise Manager 12c is really simple. I personally configured a complete cloud environment with three X86 servers and a small JBOD san box in less than 3 hours. There is no magic in it, it is all straightforward. Of course, you have to have some experience with Oracle VM and Enterprise Manager. Experience in setting up Linux environments helps as well. I plan to publish a technical cookbook in the next few weeks. I hope you found this post useful and will see you again here on our blog. Any hints, comments are welcome!

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• When is a Seek not a Seek?

  - by Paul White

  The following script creates a single-column clustered table containing the integers from 1 to 1,000 inclusive. IF OBJECT_ID(N'tempdb..#Test', N'U') IS NOT NULL DROP TABLE #Test ; GO CREATE TABLE #Test ( id INTEGER PRIMARY KEY CLUSTERED ); ; INSERT #Test (id) SELECT V.number FROM master.dbo.spt_values AS V WHERE V.[type] = N'P' AND V.number BETWEEN 1 AND 1000 ; Let’s say we need to find the rows with values from 100 to 170, excluding any values that divide exactly by 10.  One way to write that query would be: SELECT T.id FROM #Test AS T WHERE T.id IN ( 101,102,103,104,105,106,107,108,109, 111,112,113,114,115,116,117,118,119, 121,122,123,124,125,126,127,128,129, 131,132,133,134,135,136,137,138,139, 141,142,143,144,145,146,147,148,149, 151,152,153,154,155,156,157,158,159, 161,162,163,164,165,166,167,168,169 ) ; That query produces a pretty efficient-looking query plan: Knowing that the source column is defined as an INTEGER, we could also express the query this way: SELECT T.id FROM #Test AS T WHERE T.id >= 101 AND T.id <= 169 AND T.id % 10 > 0 ; We get a similar-looking plan: If you look closely, you might notice that the line connecting the two icons is a little thinner than before.  The first query is estimated to produce 61.9167 rows – very close to the 63 rows we know the query will return.  The second query presents a tougher challenge for SQL Server because it doesn’t know how to predict the selectivity of the modulo expression (T.id % 10 > 0).  Without that last line, the second query is estimated to produce 68.1667 rows – a slight overestimate.  Adding the opaque modulo expression results in SQL Server guessing at the selectivity.  As you may know, the selectivity guess for a greater-than operation is 30%, so the final estimate is 30% of 68.1667, which comes to 20.45 rows. The second difference is that the Clustered Index Seek is costed at 99% of the estimated total for the statement.  For some reason, the final SELECT operator is assigned a small cost of 0.0000484 units; I have absolutely no idea why this is so, or what it models.  Nevertheless, we can compare the total cost for both queries: the first one comes in at 0.0033501 units, and the second at 0.0034054.  The important point is that the second query is costed very slightly higher than the first, even though it is expected to produce many fewer rows (20.45 versus 61.9167). If you run the two queries, they produce exactly the same results, and both complete so quickly that it is impossible to measure CPU usage for a single execution.  We can, however, compare the I/O statistics for a single run by running the queries with STATISTICS IO ON: Table '#Test'. Scan count 63, logical reads 126, physical reads 0. Table '#Test'. Scan count 01, logical reads 002, physical reads 0. The query with the IN list uses 126 logical reads (and has a ‘scan count’ of 63), while the second query form completes with just 2 logical reads (and a ‘scan count’ of 1).  It is no coincidence that 126 = 63 * 2, by the way.  It is almost as if the first query is doing 63 seeks, compared to one for the second query. In fact, that is exactly what it is doing.  There is no indication of this in the graphical plan, or the tool-tip that appears when you hover your mouse over the Clustered Index Seek icon.  To see the 63 seek operations, you have click on the Seek icon and look in the Properties window (press F4, or right-click and choose from the menu): The Seek Predicates list shows a total of 63 seek operations – one for each of the values from the IN list contained in the first query.  I have expanded the first seek node to show the details; it is seeking down the clustered index to find the entry with the value 101.  Each of the other 62 nodes expands similarly, and the same information is contained (even more verbosely) in the XML form of the plan. Each of the 63 seek operations starts at the root of the clustered index B-tree and navigates down to the leaf page that contains the sought key value.  Our table is just large enough to need a separate root page, so each seek incurs 2 logical reads (one for the root, and one for the leaf).  We can see the index depth using the INDEXPROPERTY function, or by using the a DMV: SELECT S.index_type_desc, S.index_depth FROM sys.dm_db_index_physical_stats ( DB_ID(N'tempdb'), OBJECT_ID(N'tempdb..#Test', N'U'), 1, 1, DEFAULT ) AS S ; Let’s look now at the Properties window when the Clustered Index Seek from the second query is selected: There is just one seek operation, which starts at the root of the index and navigates the B-tree looking for the first key that matches the Start range condition (id >= 101).  It then continues to read records at the leaf level of the index (following links between leaf-level pages if necessary) until it finds a row that does not meet the End range condition (id <= 169).  Every row that meets the seek range condition is also tested against the Residual Predicate highlighted above (id % 10 > 0), and is only returned if it matches that as well. You will not be surprised that the single seek (with a range scan and residual predicate) is much more efficient than 63 singleton seeks.  It is not 63 times more efficient (as the logical reads comparison would suggest), but it is around three times faster.  Let’s run both query forms 10,000 times and measure the elapsed time: DECLARE @i INTEGER, @n INTEGER = 10000, @s DATETIME = GETDATE() ; SET NOCOUNT ON; SET STATISTICS XML OFF; ; WHILE @n > 0 BEGIN SELECT @i = T.id FROM #Test AS T WHERE T.id IN ( 101,102,103,104,105,106,107,108,109, 111,112,113,114,115,116,117,118,119, 121,122,123,124,125,126,127,128,129, 131,132,133,134,135,136,137,138,139, 141,142,143,144,145,146,147,148,149, 151,152,153,154,155,156,157,158,159, 161,162,163,164,165,166,167,168,169 ) ; SET @n -= 1; END ; PRINT DATEDIFF(MILLISECOND, @s, GETDATE()) ; GO DECLARE @i INTEGER, @n INTEGER = 10000, @s DATETIME = GETDATE() ; SET NOCOUNT ON ; WHILE @n > 0 BEGIN SELECT @i = T.id FROM #Test AS T WHERE T.id >= 101 AND T.id <= 169 AND T.id % 10 > 0 ; SET @n -= 1; END ; PRINT DATEDIFF(MILLISECOND, @s, GETDATE()) ; On my laptop, running SQL Server 2008 build 4272 (SP2 CU2), the IN form of the query takes around 830ms and the range query about 300ms.  The main point of this post is not performance, however – it is meant as an introduction to the next few parts in this mini-series that will continue to explore scans and seeks in detail. When is a seek not a seek?  When it is 63 seeks © Paul White 2011 email: [email protected] twitter: @SQL_kiwi

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• Developing Schema Compare for Oracle (Part 1)

  - by Simon Cooper

  SQL Compare is one of Red Gate's most successful SQL Server tools; it allows developers and DBAs to compare and synchronize the contents of their databases. Although similar tools exist for Oracle, they are quite noticeably lacking in the usability and stability that SQL Compare is known for in the SQL Server world. We could see a real need for a usable schema comparison tools for Oracle, and so the Schema Compare for Oracle project was born. Over the next few weeks, as we come up to release of v1, I'll be doing a series of posts on the development of Schema Compare for Oracle. For the first post, I thought I would start with the main pitfalls that we stumbled across when developing the product, especially from a SQL Server background. 1. Schemas and Databases The most obvious difference is that the concept of a 'database' is quite different between Oracle and SQL Server. On SQL Server, one server instance has multiple databases, each with separate schemas. There is typically little communication between separate databases, and most databases are no more than about 1000-2000 objects. This means SQL Compare can register an entire database in a reasonable amount of time, and cross-database dependencies probably won't be an issue. It is a quite different scene under Oracle, however. The terms 'database' and 'instance' are used interchangeably, (although technically 'database' refers to the datafiles on disk, and 'instance' the running Oracle process that reads & writes to the database), and a database is a single conceptual entity. This immediately presents problems, as it is infeasible to register an entire database as we do in SQL Compare; in my Oracle install, using the standard recommended options, there are 63975 system objects. If we tried to register all those, not only would it take hours, but the client would probably run out of memory before we finished. As a result, we had to allow people to specify what schemas they wanted to register. This decision had quite a few knock-on effects for the design, which I will cover in a future post. 2. Connecting to Oracle The next obvious difference is in actually connecting to Oracle – in SQL Server, you can specify a server and database, and off you go. On Oracle things are slightly more complicated. SIDs, Service Names, and TNS A database (the files on disk) must have a unique identifier for the databases on the system, called the SID. It also has a global database name, which consists of a name (which doesn't have to match the SID) and a domain. Alternatively, you can identify a database using a service name, which normally has a 1-to-1 relationship with instances, but may not if, for example, using RAC (Real Application Clusters) for redundancy and failover. You specify the computer and instance you want to connect to using TNS (Transparent Network Substrate). The user-visible parts are a config file (tnsnames.ora) on the client machine that specifies how to connect to an instance. For example, the entry for one of my test instances is: SC_11GDB1 = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = simonctest)(PORT = 1521)) ) (CONNECT_DATA = (SID = 11gR1db1) ) ) This gives the hostname, port, and SID of the instance I want to connect to, and associates it with a name (SC_11GDB1). The tnsnames syntax also allows you to specify failover, multiple descriptions and address lists, and client load balancing. You can then specify this TNS identifier as the data source in a connection string. Although using ODP.NET (the .NET dlls provided by Oracle) was fine for internal prototype builds, once we released the EAP we discovered that this simply wasn't an acceptable solution for installs on other people's machines. Due to .NET assembly strong naming, users had to have installed on their machines the exact same version of the ODP.NET dlls as we had on our build server. We couldn't ship the ODP.NET dlls with our installer as the Oracle license agreement prohibited this, and we didn't want to force users to install another Oracle client just so they can run our program. To be able to list the TNS entries in the connection dialog, we also had to locate and parse the tnsnames.ora file, which was complicated by users with several Oracle client installs and intricate TNS entries. After much swearing at our computers, we eventually decided to use a third party Oracle connection library from Devart that we could ship with our program; this could use whatever client version was installed, parse the TNS entries for us, and also had the nice feature of being able to connect to an Oracle server without having any client installed at all. Unfortunately, their current license agreement prevents us from shipping an Oracle SDK, but that's a bridge we'll cross when we get to it. 3. Running synchronization scripts The most important difference is that in Oracle, DDL is non-transactional; you cannot rollback DDL statements like you can on SQL Server. Although we considered various solutions to this, including using the flashback archive or recycle bin, or generating an undo script, no reliable method of completely undoing a half-executed sync script has yet been found; so in this case we simply have to trust that the DBA or developer will check and verify the script before running it. However, before we got to that stage, we had to get the scripts to run in the first place... To run a synchronization script from SQL Compare we essentially pass the script over to the SqlCommand.ExecuteNonQuery method. However, when we tried to do the same for an OracleConnection we got a very strange error – 'ORA-00911: invalid character', even when running the most basic CREATE TABLE command. After much hair-pulling and Googling, we discovered that Oracle has got some very strange behaviour with semicolons at the end of statements. To understand what's going on, we need to take a quick foray into SQL and PL/SQL. PL/SQL is not T-SQL In SQL Server, T-SQL is the language used to interface with the database. It has DDL, DML, control flow, and many other nice features (like Turing-completeness) that you can mix and match in the same script. In Oracle, DDL SQL and PL/SQL are two completely separate languages, with different syntax, different datatypes and different execution engines within the instance. Oracle SQL is much more like 'pure' ANSI SQL, with no state, no control flow, and only the basic DML commands. PL/SQL is the Turing-complete language, but can only do DML and DCL (i.e. BEGIN TRANSATION commands). Any DDL or SQL commands that aren't recognised by the PL/SQL engine have to be passed back to the SQL engine via an EXECUTE IMMEDIATE command. In PL/SQL, a semicolons is a valid token used to delimit the end of a statement. In SQL, a semicolon is not a valid token (even though the Oracle documentation gives them at the end of the syntax diagrams) . When you execute the command CREATE TABLE table1 (COL1 NUMBER); in SQL*Plus the semicolon on the end is a command to SQL*Plus to execute the preceding statement on the server; it strips off the semicolon before passing it on. SQL Developer does a similar thing. When executing a PL/SQL block, however, the syntax is like so: BEGIN INSERT INTO table1 VALUES (1); INSERT INTO table1 VALUES (2); END; / In this case, the semicolon is accepted by the PL/SQL engine as a statement delimiter, and instead the / is the command to SQL*Plus to execute the current block. This explains the ORA-00911 error we got when trying to run the CREATE TABLE command – the server is complaining about the semicolon on the end. This also means that there is no SQL syntax to execute more than one DDL command in the same OracleCommand. Therefore, we would have to do a round-trip to the server for every command we want to execute. Obviously, this would cause lots of network traffic and be very slow on slow or congested networks. Our first attempt at a solution was to wrap every SQL statement (without semicolon) inside an EXECUTE IMMEDIATE command in a PL/SQL block and pass that to the server to execute. One downside of this solution is that we get no feedback as to how the script execution is going; we're currently evaluating better solutions to this thorny issue. Next up: Dependencies; how we solved the problem of being unable to register the entire database, and the knock-on effects to the whole product.

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