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• XBRL - Moving from Production to Consumption

  - by jmorourke

  Here's an update on what’s new with XBRL and how it can actually benefit your organization versus adding extra time and costs to financial reporting.  On February 29th (leap day) of 2012 I attended the XBRL and Financial Analysis Technology Conference at Baruch College in NYC.  The event, which attracted over 300 XBRL gurus and fans was presented by XBRL US, The New York Society of Security Analysts’ Improved Corporate Reporting Committee, and Baruch College’s Robert Zicklin Center for Corporate Integrity.  The event featured keynotes from the U.S. Securities and Exchange Commission (SEC), and the CFA Institute as well as panels covering alternative research tools and data, corporate reporting to stakeholders and a demonstration of XBRL analysis tools.  The program culminated in a presentation of the finalists and the winner of the $20,000 XBRL Challenge.    Some of the key points made in the sessions included: The focus of XBRL tools is moving from production to consumption. As of February 2012, over 9000 companies are reporting in XBRL, with over 10 million facts filed to date XBRL taxonomy extensions have dropped from 27% to 11% making comparisons easier The SEC reports that XBRL makes it easier to analyze disclosures, focus on accounting issues XBRL is helping standards-setters like the FASB speed their analysis of impacts of proposed accounting rule changes Companies like Thomson Reuters report that XBRL is helping speed the delivery of data to clients The most interesting part of the program though, was the session highlighting the 5 finalists in the XBRL Challenge competition and the winning solution.  The XBRL Challenge was launched in 2011 as a means of spurring the development of more end-user tools to help with the consumption of XBRL-based financial information.       Over an 8-month process handled by 5 judges, there were 84 registrants, 15 completed submissions, 5 finalists and one winner of the challenge.  All of the solutions are open-sourced tools and most of them focus on consuming XBRL-based data.  The 5 finalists included: Advanced XBRL Processing from Oxide solutions – XBRL viewer for taxonomies, filings and company data with peer comparison capabilities. Arrelle – API for XBRL processes, supports SEC Validations, RSS Feeds to access filings etc. Calcbench – XBRL data analysis tool that can be embedded in other web applications.  This tool can combine XBRL filings with real-time market data. XBRL to XL – allows the importing of XBRL data into Microsoft Excel for analysis, comparisons.  Users start on the web and populate Excel with XBRL data. XBurble – allows users to search and view XBRL filings, export to Excel, merge for comparison, and includes a workflow interface. The winner of the $20,000 XBRL Challenge prize was CalcBench.  More information about the XBRL Challenge and the finalists can be found at www.XBRLUS.org/challenge XBRL for Sustainability Reporting – other recent news on the XBRL front was the announcement by the Global Reporting Initiative (GRI) of an XBRL taxonomy for Sustainability Reporting.  This taxonomy was co-developed by the GRI and Deloitte and is designed to make the consumption of data found in Sustainability Reports much easier.  Although there is no government mandate to file Sustainability Reports in XBRL format, organizations that do use the GRI guidelines for Sustainability Reporting are encouraged to tag and submit their data voluntarily to the GRI – who will populate a database with Sustainability Reporting data and make this available to the public.  For more information about this initiative, you can go to the GRI web site:  www.globalreporting.org. So how does all of this benefit corporate filers and investors?  Since its introduction, the consensus in the market is that XBRL has mainly benefited the regulators and investment analysts who need to consume and analyze large volumes of financial data.  But with the emergence of more end-user tools for consuming and analyzing XBRL-based data, and the ability to perform quick comparisons of one company versus its peers and competitors in an industry group, will soon accelerate the benefits to corporate finance staff, as well as individual investors.  This could apply to financial results tagged in XBRL, as well as non-financial information such as Sustainability Reporting – which over the long-term will likely be integrated with financial reporting.   And as multiple regulators and agencies in a country adopt the XBRL standard for corporate filings, more benefits will accrue as companies will be able to leverage one set of XBRL-based financial data for multiple regulatory filings.     For more information about the latest developments in XBRL, check out the XBRL US or XBRL International web sites:  www.xbrl.org, www.xbrlus.org. For more information about what Oracle is doing to support XBRL, here are some links: http://www.oracle.com/us/solutions/ent-performance-bi/disclosure-management-065892.html http://www.oracle.com/technetwork/database/features/xmldb/index-087631.html Feel free to contact me if you have any questions or need more information:  [email protected]

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• XmlWriter and lower ASCII characters

  - by Rick Strahl

  Ran into an interesting problem today on my CodePaste.net site: The main RSS and ATOM feeds on the site were broken because one code snippet on the site contained a lower ASCII character (CHR(3)). I don't think this was done on purpose but it was enough to make the feeds fail. After quite a bit of debugging and throwing in a custom error handler into my actual feed generation code that just spit out the raw error instead of running it through the ASP.NET MVC and my own error pipeline I found the actual error. The lovely base exception and error trace I got looked like this: Error: '', hexadecimal value 0x03, is an invalid character. at System.Xml.XmlUtf8RawTextWriter.InvalidXmlChar(Int32 ch, Byte* pDst, Boolean entitize)at System.Xml.XmlUtf8RawTextWriter.WriteElementTextBlock(Char* pSrc, Char* pSrcEnd)at System.Xml.XmlUtf8RawTextWriter.WriteString(String text)at System.Xml.XmlWellFormedWriter.WriteString(String text)at System.Xml.XmlWriter.WriteElementString(String localName, String ns, String value)at System.ServiceModel.Syndication.Rss20FeedFormatter.WriteItemContents(XmlWriter writer, SyndicationItem item, Uri feedBaseUri)at System.ServiceModel.Syndication.Rss20FeedFormatter.WriteItem(XmlWriter writer, SyndicationItem item, Uri feedBaseUri)at System.ServiceModel.Syndication.Rss20FeedFormatter.WriteItems(XmlWriter writer, IEnumerable`1 items, Uri feedBaseUri)at System.ServiceModel.Syndication.Rss20FeedFormatter.WriteFeed(XmlWriter writer)at System.ServiceModel.Syndication.Rss20FeedFormatter.WriteTo(XmlWriter writer)at CodePasteMvc.Controllers.ApiControllerBase.GetFeed(Object instance) in C:\Projects2010\CodePaste\CodePasteMvc\Controllers\ApiControllerBase.cs:line 131 XML doesn't like extended ASCII Characters It turns out the issue is that XML in general does not deal well with lower ASCII characters. According to the XML spec it looks like any characters below 0x09 are invalid. If you generate an XML document in .NET with an embedded &#x3; entity (as mine did to create the error above), you tend to get an XML document error when displaying it in a viewer. For example, here's what the result of my  feed output looks like with the invalid character embedded inside of Chrome which displays RSS feeds as raw XML by default: Other browsers show similar error messages. The nice thing about Chrome is that you can actually view source and jump down to see the line that causes the error which allowed me to track down the actual message that failed. If you create an XML document that contains a 0x03 character the XML writer fails outright with the error: '', hexadecimal value 0x03, is an invalid character. The good news is that this behavior is overridable so XML output can at least be created by using the XmlSettings object when configuring the XmlWriter instance. In my RSS configuration code this looks something like this:MemoryStream ms = new MemoryStream(); var settings = new XmlWriterSettings() { CheckCharacters = false }; XmlWriter writer = XmlWriter.Create(ms,settings); and voila the feed now generates. Now generally this is probably NOT a good idea, because as mentioned above these characters are illegal and if you view a raw XML document you'll get validation errors. Luckily though most RSS feed readers however don't care and happily accept and display the feed correctly, which is good because it got me over an embarrassing hump until I figured out a better solution. How to handle extended Characters? I was glad to get the feed fixed for the time being, but now I was still stuck with an interesting dilemma. CodePaste.net accepts user input for code snippets and those code snippets can contain just about anything. This means that ASP.NET's standard request filtering cannot be applied to this content. The code content displayed is encoded before display so for the HTML end the CHR(3) input is not really an issue. While invisible characters are hardly useful in user input it's not uncommon that odd characters show up in code snippets. You know the old fat fingering that happens when you're in the middle of a coding session and those invisible characters do end up sometimes in code editors and then end up pasted into the HTML textbox for pasting as a Codepaste.net snippet. The question is how to filter this text? Looking back at the XML Charset Spec it looks like all characters below 0x20 (space) except for 0x09 (tab), 0x0A (LF), 0x0D (CR) are illegal. So applying the following filter with a RegEx should work to remove invalid characters:string code = Regex.Replace(item.Code, @"[\u0000-\u0008,\u000B,\u000C,\u000E-\u001F]", ""); Applying this RegEx to the code snippet (and title) eliminates the problems and the feed renders cleanly.© Rick Strahl, West Wind Technologies, 2005-2012Posted in .NET  XML   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• Project of Projects with team Foundation Server 2010

  - by Martin Hinshelwood

  It is pretty much accepted that you should use Areas instead of having many small Team Projects when you are using Team Foundation Server 2010. I have implemented this scenario many times and this is the current iteration of layout and considerations. If like me you work with many customers you will find that you get into a grove for how to set these things up to make them as easily understandable for everyone, while giving the best functionality. The trick is in making it as intuitive as possible for both you and the developers that need to work with it. There are five main places where you need to have the Product or Project name in prominence of any other value. Area Iteration Source Code Work Item Queries Build Once you decide how you are doing this in each of these places you need to keep to it religiously. Evan if you have one source code file to keep, make sure it is in the right place. This makes your developers and others working with the format familiar with where everything should go, as well as building up mussel memory. This prevents the neat system degenerating into a nasty mess. Areas Areas are traditionally used to separate out parts of your product / project so that you can see how much effort has gone into each. Figure: The top level areas are for reporting and work item separation There are massive advantages of using this method. You can: move work from one project to another rename a project / product It is far more likely that a project or product gets renamed than a department. Tip: If you have many projects, over 100, you should consider categorising them here, but make sure that the actual project name always sits at the same level so you know which is which. Figure: Always keep things that are the same at the same level Note: You may use these categories only at the Area/Iteration level to make it easier to select on drop down lists. You may not want to use them everywhere. On the other hand, for consistency it would be better to. Iterations Iterations are usually used to some sort of time based consideration. Here I am splitting into Iterations with periodic releases. Figure: Each product needs to be able to have its own cadence The ability to have each project run at its own pace and to enable them to have their own release schedule is often of paramount importance and you don’t want to fix your 100+ projects to all be released on the same date. Source Code Having a good structure for your source even if you are not branching or having multiple products under the same structure is always a good idea. Figure: Separate out your products source You need to think about both your branches as well as the structure of your source. All your code should be under “Source” and everything you need to build your solution including Build Scripts and 3rd party tools should be under your “Main” (branch) folder. This should them be branched by “Quality”, “Release” or both to get the most out of your branching structure. The important thing is to make sure you branch (or be able to branch) everything you need to build, test and deploy your application to an environment. That environment may be development, test or even production, but I can’t stress the importance of having everything your need. Note: You usually will not be able to install custom software on your build server. Store any *.dll’s or *.exe’s that you need under the “Tools\Tool1” folder. Note: Consult the Branching Guidance for Team Foundation Server 2010 for more on branching Figure: Adding category may be a necessary evil Even if you have to have a couple of categories called “Default”, it is better than not knowing the difference between a folder, Product and Branch. Work Item Queries Queries are used to load lists of Work Items out of TFS so you can see what work you have. This means that you want to also separate queries out by Product / project to make it easier to Figure: Again you have the same first level structure Having Folders also in Work Item Tracking we do the same thing. We put all the queries under a folder named for the Product / Project and change each query to have “AreaPath=[TeamProject]\[ProductX]” in the query instead of the standard “Project=@Project”. Tip: Don’t have a folder with new queries for each iteration. Instead have a single “Current” folder that has queries that point to the current iteration. Just change the queries as you move from one iteration to another. Tip: You can ctrl+drag the “Product1” folder to create your “Product2” folder. Builds You may have many builds both for individual products but also for different quality's. This can be further complicated by having some builds that action “Gated Check-In” and others that are specifically for “Release”, “Test” or another purpose. Figure: There are no folders, yet, for the builds so you need a good naming convention Its a pity that there are no folders under builds, some way to categorise would be nice. In lue of that at the moment you can use a functional naming convention that at least allows you to find what you want. Conclusion It is really easy to both achieve and to stick to this format if you take the time to do it. Unless you have 1000+ builds or 100+ Products you are unlikely run into any issues. Even then there are things you can do to mitigate the issues and I have describes some of them above. Let me know if you can think of any other things to make this easier.

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• Example: Controlling randomizer using code contracts

  - by DigiMortal

  One cool addition to Visual Studio 2010 is support for code contracts. Code contracts make sure that all conditions under what method is supposed to run correctly are met. Those who are familiar with unit tests will find code contracts easy to use. In this posting I will show you simple example about static contract checking (example solution is included). To try out code contracts you need at least Visual Studio 2010 Standard Edition. Also you need code contracts package. You can download package from DevLabs Code Contracts page. NB! Speakers, you can use the example solution in your presentations as long as you mention me and this blog in your sessions. Solution has readme.txt file that gives you steps to go through when presenting solution in sessions. This blog posting is companion posting for Visual Studio solution referred below. As an example let’s look at the following class. public class Randomizer {     public static int GetRandomFromRange(int min, int max)     {         var rnd = new Random();         return rnd.Next(min, max);     }       public static int GetRandomFromRangeContracted(int min, int max)     {         Contract.Requires(min < max, "Min must be less than max");           var rnd = new Random();         return rnd.Next(min, max);     } } GetRandomFromRange() method returns results without any checking. GetRandomFromRangeContracted() uses one code contract that makes sure that minimum value is less than maximum value. Now let’s run the following code. class Program {     static void Main(string[] args)     {         var random1 = Randomizer.GetRandomFromRange(0, 9);         Console.WriteLine("Random 1: " + random1);           var random2 = Randomizer.GetRandomFromRange(1, 1);         Console.WriteLine("Random 2: " + random2);           var random3 = Randomizer.GetRandomFromRangeContracted(5, 5);         Console.WriteLine("Random 3: " + random3);           Console.WriteLine(" ");         Console.WriteLine("Press any key to exit ...");         Console.ReadKey();     } } As we have not turned on support for code contracts the code runs without any problems and we get no warnings by Visual Studio that something is wrong. Now let’s turn on static checking for code contracts. As you can see then code still compiles without any errors but Visual Studio warns you about possible problems with contracts. Click on image to see it at original size.  When we open Error list and run our application we get the following output to errors list. Note that these messages are not shown immediately. There is little delay between application starting and appearance of these messages. So wait couple of seconds before going out of your mind. Click on image to see it at original size.  If you look at these warnings you can see that warnings show you illegal calls and also contracts against what they are going. Third warning points to GetRandomFromRange() method and shows that there should be also problem that can be detected by contract. Download Code Contracts example VS2010 solution | 30KB

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• SQL SERVER – ?Finding Out What Changed in a Deleted Database – Notes from the Field #041

  - by Pinal Dave

  [Note from Pinal]: This is a 41th episode of Notes from the Field series. The real world is full of challenges. When we are reading theory or book, we sometimes do not realize how real world reacts works and that is why we have the series notes from the field, which is extremely popular with developers and DBA. Let us talk about interesting problem of how to figure out what has changed in the DELETED database. Well, you think I am just throwing the words but in reality this kind of problems are making our DBA’s life interesting and in this blog post we have amazing story from Brian Kelley about the same subject. In this episode of the Notes from the Field series database expert Brian Kelley explains a how to find out what has changed in deleted database. Read the experience of Brian in his own words. Sometimes, one of the hardest questions to answer is, “What changed?” A similar question is, “Did anything change other than what we expected to change?” The First Place to Check – Schema Changes History Report: Pinal has recently written on the Schema Changes History report and its requirement for the Default Trace to be enabled. This is always the first place I look when I am trying to answer these questions. There are a couple of obvious limitations with the Schema Changes History report. First, while it reports what changed, when it changed, and who changed it, other than the base DDL operation (CREATE, ALTER, DELETE), it does not present what the changes actually were. This is not something covered by the default trace. Second, the default trace has a fixed size. When it hits that size, the changes begin to overwrite. As a result, if you wait too long, especially on a busy database server, you may find your changes rolled off. But the Database Has Been Deleted! Pinal cited another issue, and that’s the inability to run the Schema Changes History report if the database has been dropped. Thankfully, all is not lost. One thing to remember is that the Schema Changes History report is ultimately driven by the Default Trace. As you may have guess, it’s a trace, like any other database trace. And the Default Trace does write to disk. The trace files are written to the defined LOG directory for that SQL Server instance and have a prefix of log_: Therefore, you can read the trace files like any other. Tip: Copy the files to a working directory. Otherwise, you may occasionally receive a file in use error. With the Default Trace files, if you ask the question early enough, you can see the information for a deleted database just the same as any other database. Testing with a Deleted Database: Here’s a short script that will create a database, create a schema, create an object, and then drop the database. Without the database, you can’t do a standard Schema Changes History report. CREATE DATABASE DeleteMe; GO USE DeleteMe; GO CREATE SCHEMA Test AUTHORIZATION dbo; GO CREATE TABLE Test.Foo (FooID INT); GO USE MASTER; GO DROP DATABASE DeleteMe; GO This sets up the perfect situation where we can’t retrieve the information using the Schema Changes History report but where it’s still available. Finding the Information: I’ve sorted the columns so I can see the Event Subclass, the Start Time, the Database Name, the Object Name, and the Object Type at the front, but otherwise, I’m just looking at the trace files using SQL Profiler. As you can see, the information is definitely there: Therefore, even in the case of a dropped/deleted database, you can still determine who did what and when. You can even determine who dropped the database (loginame is captured). The key is to get the default trace files in a timely manner in order to extract the information. If you want to get started with performance tuning and database security with the help of experts, read more over at Fix Your SQL Server. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: Notes from the Field, PostADay, SQL, SQL Authority, SQL Query, SQL Security, SQL Server, SQL Tips and Tricks, T SQL

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• Node Serialization in NetBeans Platform 7.0

  - by Geertjan

  Node serialization makes sense when you're not interested in the data (since that should be serialized to a database), but in the state of the application. For example, when the application restarts, you want the last selected node to automatically be selected again. That's not the kind of information you'll want to store in a database, hence node serialization is not about data serialization but about application state serialization. I've written about this topic in October 2008, here and here, but want to show how to do this again, using NetBeans Platform 7.0. Somewhere I remember reading that this can't be done anymore and that's typically the best motivation for me, i.e., to prove that it can be done after all. Anyway, in a standard POJO/Node/BeanTreeView scenario, do the following: Remove the "@ConvertAsProperties" annotation at the top of the class, which you'll find there if you used the Window Component wizard. We're not going to use property-file based serialization, but plain old java.io.Serializable  instead. In the TopComponent, assuming it is named "UserExplorerTopComponent", typically at the end of the file, add the following: @Override public Object writeReplace() { //We want to work with one selected item only //and thanks to BeanTreeView.setSelectionMode, //only one node can be selected anyway: Handle handle = NodeOp.toHandles(em.getSelectedNodes())[0]; return new ResolvableHelper(handle); } public final static class ResolvableHelper implements Serializable { private static final long serialVersionUID = 1L; public Handle selectedHandle; private ResolvableHelper(Handle selectedHandle) { this.selectedHandle = selectedHandle; } public Object readResolve() { WindowManager.getDefault().invokeWhenUIReady(new Runnable() { @Override public void run() { try { //Get the TopComponent: UserExplorerTopComponent tc = (UserExplorerTopComponent) WindowManager.getDefault().findTopComponent("UserExplorerTopComponent"); //Get the display text to search for: String selectedDisplayName = selectedHandle.getNode().getDisplayName(); //Get the root, which is the parent of the node we want: Node root = tc.getExplorerManager().getRootContext(); //Find the node, by passing in the root with the display text: Node selectedNode = NodeOp.findPath(root, new String[]{selectedDisplayName}); //Set the explorer manager's selected node: tc.getExplorerManager().setSelectedNodes(new Node[]{selectedNode}); } catch (PropertyVetoException ex) { Exceptions.printStackTrace(ex); } catch (IOException ex) { Exceptions.printStackTrace(ex); } } }); return null; } } Assuming you have a node named "UserNode" for a type named "User" containing a property named "type", add the bits in bold below to your "UserNode": public class UserNode extends AbstractNode implements Serializable { static final long serialVersionUID = 1L; public UserNode(User key) { super(Children.LEAF); setName(key.getType()); } @Override public Handle getHandle() { return new CustomHandle(this, getName()); } public class CustomHandle implements Node.Handle { static final long serialVersionUID = 1L; private AbstractNode node = null; private final String searchString; public CustomHandle(AbstractNode node, String searchString) { this.node = node; this.searchString = searchString; } @Override public Node getNode() { node.setName(searchString); return node; } } } Run the application and select one of the user nodes. Close the application. Start it up again. The user node is not automatically selected, in fact, the window does not open, and you will see this in the output: Caused: java.io.InvalidClassException: org.serialization.sample.UserNode; no valid constructor Read this article and then you'll understand the need for this class: public class BaseNode extends AbstractNode { public BaseNode() { super(Children.LEAF); } public BaseNode(Children kids) { super(kids); } public BaseNode(Children kids, Lookup lkp) { super(kids, lkp); } } Now, instead of extending AbstractNode in your UserNode, extend BaseNode. Then the first non-serializable superclass of the UserNode has an explicitly declared no-args constructor, Do the same as the above for each node in the hierarchy that needs to be serialized. If you have multiple nodes needing serialization, you can share the "CustomHandle" inner class above between all the other nodes, while all the other nodes will also need to extend BaseNode (or provide their own non-serializable super class that explicitly declares a no-args constructor). Now, when I run the application, I select a node, then I close the application, restart it, and the previously selected node is automatically selected when the application has restarted.

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• Is Data Science “Science”?

  - by BuckWoody

  I hold the term “science” in very high esteem. I grew up on the Space Coast in Florida, and eventually worked at the Kennedy Space Center, surrounded by very intelligent people who worked in various scientific fields. Recently a new term has entered the computing dialog – “Data Scientist”. Since it’s not a standard term, it has a lot of definitions, and in fact has been disputed as a correct term. After all, the reasoning goes, if there’s no such thing as “Data Science” then how can there be a Data Scientist? This argument has been made before, albeit with a different term – “Computer Science”. In Peter Denning’s excellent article “Is Computer Science Science” (April  2005/Vol. 48, No. 4 COMMUNICATIONS OF THE ACM) there are many points that separate “science” from “engineering” and even “art”.  I won’t repeat the content of that article here (I recommend you read it on your own) but will leverage the points he makes there. Definition of Science To ask the question “is data science ‘science’” then we need to start with a definition of terms. Various references put the definition into the same basic areas: Study of the physical world Systematic and/or disciplined study of a subject area ...and then they include the things studied, the bodies of knowledge and so on. The word itself comes from Latin, and means merely “to know” or “to study to know”. Greek divides knowledge further into “truth” (episteme), and practical use or effects (tekhne). Normally computing falls into the second realm. Definition of Data Science And now a more controversial definition: Data Science. This term is so new and perhaps so niche that the major dictionaries haven’t yet picked it up (my OED reference is older – can’t afford to pop for the online registration at present). Researching the term's general use I created an amalgam of the definitions this way: “Studying and applying mathematical and other techniques to derive information from complex data sets.” Using this definition, data science certainly seems to be science - it's learning about and studying some object or area using systematic methods. But implicit within the definition is the word “application”, which makes the process more akin to engineering or even technology than science. In fact, I find that using these techniques – and data itself – part of science, not science itself. I leave out the concept of studying data patterns or algorithms as part of this discipline. That is actually a domain I see within research, mathematics or computer science. That of course is a type of science, but does not seek for practical applications. As part of the argument against calling it “Data Science”, some point to the scientific method of creating a hypothesis, testing with controls, testing results against the hypothesis, and documenting for repeatability.  These are not steps that we often take in working with data. We normally start with a question, and fit patterns and algorithms to predict outcomes and find correlations. In this way Data Science is more akin to statistics (and in fact makes heavy use of them) in the process rather than starting with an assumption and following on with it. So, is Data Science “Science”? I’m uncertain – and I’m uncertain it matters. Even if we are facing rampant “title inflation” these days (does anyone introduce themselves as a secretary or supervisor anymore?) I can tolerate the term at least from the intent that we use data to study problems across a wide spectrum, rather than restricting it to a single domain. And I also understand those who have worked hard to achieve the very honorable title of “scientist” who have issues with those who borrow the term without asking. What do you think? Science, or not? Does it matter?

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• Subterranean IL: The ThreadLocal type

  - by Simon Cooper

  I came across ThreadLocal<T> while I was researching ConcurrentBag. To look at it, it doesn't really make much sense. What's all those extra Cn classes doing in there? Why is there a GenericHolder<T,U,V,W> class? What's going on? However, digging deeper, it's a rather ingenious solution to a tricky problem. Thread statics Declaring that a variable is thread static, that is, values assigned and read from the field is specific to the thread doing the reading, is quite easy in .NET: [ThreadStatic] private static string s_ThreadStaticField; ThreadStaticAttribute is not a pseudo-custom attribute; it is compiled as a normal attribute, but the CLR has in-built magic, activated by that attribute, to redirect accesses to the field based on the executing thread's identity. TheadStaticAttribute provides a simple solution when you want to use a single field as thread-static. What if you want to create an arbitary number of thread static variables at runtime? Thread-static fields can only be declared, and are fixed, at compile time. Prior to .NET 4, you only had one solution - thread local data slots. This is a lesser-known function of Thread that has existed since .NET 1.1: LocalDataStoreSlot threadSlot = Thread.AllocateNamedDataSlot("slot1"); string value = "foo"; Thread.SetData(threadSlot, value); string gettedValue = (string)Thread.GetData(threadSlot); Each instance of LocalStoreDataSlot mediates access to a single slot, and each slot acts like a separate thread-static field. As you can see, using thread data slots is quite cumbersome. You need to keep track of LocalDataStoreSlot objects, it's not obvious how instances of LocalDataStoreSlot correspond to individual thread-static variables, and it's not type safe. It's also relatively slow and complicated; the internal implementation consists of a whole series of classes hanging off a single thread-static field in Thread itself, using various arrays, lists, and locks for synchronization. ThreadLocal<T> is far simpler and easier to use. ThreadLocal ThreadLocal provides an abstraction around thread-static fields that allows it to be used just like any other class; it can be used as a replacement for a thread-static field, it can be used in a List<ThreadLocal<T>>, you can create as many as you need at runtime. So what does it do? It can't just have an instance-specific thread-static field, because thread-static fields have to be declared as static, and so shared between all instances of the declaring type. There's something else going on here. The values stored in instances of ThreadLocal<T> are stored in instantiations of the GenericHolder<T,U,V,W> class, which contains a single ThreadStatic field (s_value) to store the actual value. This class is then instantiated with various combinations of the Cn types for generic arguments. In .NET, each separate instantiation of a generic type has its own static state. For example, GenericHolder<int,C0,C1,C2> has a completely separate s_value field to GenericHolder<int,C1,C14,C1>. This feature is (ab)used by ThreadLocal to emulate instance thread-static fields. Every time an instance of ThreadLocal is constructed, it is assigned a unique number from the static s_currentTypeId field using Interlocked.Increment, in the FindNextTypeIndex method. The hexadecimal representation of that number then defines the specific Cn types that instantiates the GenericHolder class. That instantiation is therefore 'owned' by that instance of ThreadLocal. This gives each instance of ThreadLocal its own ThreadStatic field through a specific unique instantiation of the GenericHolder class. Although GenericHolder has four type variables, the first one is always instantiated to the type stored in the ThreadLocal<T>. This gives three free type variables, each of which can be instantiated to one of 16 types (C0 to C15). This puts an upper limit of 4096 (163) on the number of ThreadLocal<T> instances that can be created for each value of T. That is, there can be a maximum of 4096 instances of ThreadLocal<string>, and separately a maximum of 4096 instances of ThreadLocal<object>, etc. However, there is an upper limit of 16384 enforced on the total number of ThreadLocal instances in the AppDomain. This is to stop too much memory being used by thousands of instantiations of GenericHolder<T,U,V,W>, as once a type is loaded into an AppDomain it cannot be unloaded, and will continue to sit there taking up memory until the AppDomain is unloaded. The total number of ThreadLocal instances created is tracked by the ThreadLocalGlobalCounter class. So what happens when either limit is reached? Firstly, to try and stop this limit being reached, it recycles GenericHolder type indexes of ThreadLocal instances that get disposed using the s_availableIndices concurrent stack. This allows GenericHolder instantiations of disposed ThreadLocal instances to be re-used. But if there aren't any available instantiations, then ThreadLocal falls back on a standard thread local slot using TLSHolder. This makes it very important to dispose of your ThreadLocal instances if you'll be using lots of them, so the type instantiations can be recycled. The previous way of creating arbitary thread-static variables, thread data slots, was slow, clunky, and hard to use. In comparison, ThreadLocal can be used just like any other type, and each instance appears from the outside to be a non-static thread-static variable. It does this by using the CLR type system to assign each instance of ThreadLocal its own instantiated type containing a thread-static field, and so delegating a lot of the bookkeeping that thread data slots had to do to the CLR type system itself! That's a very clever use of the CLR type system.

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• EM CLI, diving in and beyond!

  - by Maureen Byrne

  v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Doing more in less time… Isn’t that what we all strive to do? With this in mind, I put together two screen watches on Oracle Enterprise Manager 12c command line interface, or EM CLI as it is also known. There is a wealth of information on any topic that you choose to read about, from manual pages to coding documents…might I even say blog posts? In our busy lives it is so nice to just sit back with a short video, watch and learn enough to dive in. Doing more in less time, is the essence of EM CLI. It enables you to script fundamental and complex administrative tasks in an elegant way, thanks to the Jython scripting language. Repetitive tasks can be scripted and reused again and again. Sure, a Graphical User Interface provides a more intuitive step by step approach to tasks, and it provides a way of quickly becoming familiar with a product and its many features, and it is definitely the way to go when viewing performance data and historical trending…but for repetitive and complex tasks, scripting is the way to go! Lets us take the everyday task of creating an administrator. Using EM CLI in interactive mode the command could look like this.. emcli>create_user(name='jan.doe', type='EXTERNAL_USER') This command creates an administrator called jan.doe which is an externally authenticated user, possibly LDAP or SSO, defined by the EXTERNAL_USER tag. The create_user procedure takes many arguments; see the documentation for more information. Now, where EM CLI really shines and shows power is in creating multiple users. Regardless of the number, tens or thousands, the effort is the same. With the use of a standard programming construct, a loop, you can place your create_user() procedure within it. Using a loop allows you to iterate through a previously created list, creating new users until the list is complete. Using EM CLI in Script mode, your Jython loop would look something like this… for user in list_of_users:       create_user(name=user, expire=’true’, password=’welcome123’) This Jython code snippet iterates through a previously defined list of names, list_of_users, and iterates through the list, taking each name, user in this case, and creates an administrator sets the password to welcome123, but forces the user to reset it when they first login. This is only one of over four hundred procedures created to expose Oracle Enterprise Manager 12c functionality in a powerful and programmatic way. It is a few months since we released EM CLI with scripting option. We are seeing many users adapt to this fun and powerful way of using Oracle Enterprise Manager 12c. What are the first steps? Watch these screen watches, and dive in. The first screen watch steps you through where and how to download and install and how to run your first few commands. The Second screen watch steps you through a few scripts. Next time, I am going to show you the basic building blocks to writing a Jython script to perform Oracle Enterprise Manager 12c administrative tasks. Join this growing group of EM CLI users…. Dive in! Normal 0 false false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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• Breaking 1NF to model subset constraints. Does this sound sane?

  - by Chris Travers

  My first question here. Appologize if it is in the wrong forum but this seems pretty conceptual. I am looking at doing something that goes against conventional wisdom and want to get some feedback as to whether this is totally insane or will result in problems, so critique away! I am on PostgreSQL 9.1 but may be moving to 9.2 for this part of this project. To re-iterate: Does it seem sane to break 1NF in this way? I am not looking for debugging code so much as where people see problems that this might lead. The Problem In double entry accounting, financial transactions are journal entries with an arbitrary number of lines. Each line has either a left value (debit) or a right value (credit) which can be modelled as a single value with negatives as debits and positives as credits or vice versa. The sum of all debits and credits must equal zero (so if we go with a single amount field, sum(amount) must equal zero for each financial journal entry). SQL-based databases, pretty much required for this sort of work, have no way to express this sort of constraint natively and so any approach to enforcing it in the database seems rather complex. The Write Model The journal entries are append only. There is a possibility we will add a delete model but it will be subject to a different set of restrictions and so is not applicable here. If and when we allow deletes, we will probably do them using a simple ON DELETE CASCADE designation on the foreign key, and require that deletes go through a dedicated stored procedure which can enforce the other constraints. So inserts and selects have to be accommodated but updates and deletes do not for this task. My Proposed Solution My proposed solution is to break first normal form and model constraints on arrays of tuples, with a trigger that breaks the rows out into another table. CREATE TABLE journal_line ( entry_id bigserial primary key, account_id int not null references account(id), journal_entry_id bigint not null, -- adding references later amount numeric not null ); I would then add "table methods" to extract debits and credits for reporting purposes: CREATE OR REPLACE FUNCTION debits(journal_line) RETURNS numeric LANGUAGE sql IMMUTABLE AS $$ SELECT CASE WHEN $1.amount < 0 THEN $1.amount * -1 ELSE NULL END; $$; CREATE OR REPLACE FUNCTION credits(journal_line) RETURNS numeric LANGUAGE sql IMMUTABLE AS $$ SELECT CASE WHEN $1.amount > 0 THEN $1.amount ELSE NULL END; $$; Then the journal entry table (simplified for this example): CREATE TABLE journal_entry ( entry_id bigserial primary key, -- no natural keys :-( journal_id int not null references journal(id), date_posted date not null, reference text not null, description text not null, journal_lines journal_line[] not null ); Then a table method and and check constraints: CREATE OR REPLACE FUNCTION running_total(journal_entry) returns numeric language sql immutable as $$ SELECT sum(amount) FROM unnest($1.journal_lines); $$; ALTER TABLE journal_entry ADD CONSTRAINT CHECK (((journal_entry.running_total) = 0)); ALTER TABLE journal_line ADD FOREIGN KEY journal_entry_id REFERENCES journal_entry(entry_id); And finally we'd have a breakout trigger: CREATE OR REPLACE FUNCTION je_breakout() RETURNS TRIGGER LANGUAGE PLPGSQL AS $$ BEGIN IF TG_OP = 'INSERT' THEN INSERT INTO journal_line (journal_entry_id, account_id, amount) SELECT NEW.id, account_id, amount FROM unnest(NEW.journal_lines); RETURN NEW; ELSE RAISE EXCEPTION 'Operation Not Allowed'; END IF; END; $$; And finally CREATE TRIGGER AFTER INSERT OR UPDATE OR DELETE ON journal_entry FOR EACH ROW EXECUTE_PROCEDURE je_breaout(); Of course the example above is simplified. There will be a status table that will track approval status allowing for separation of duties, etc. However the goal here is to prevent unbalanced transactions. Any feedback? Does this sound entirely insane? Standard Solutions? In getting to this point I have to say I have looked at four different current ERP solutions to this problems: Represent every line item as a debit and a credit against different accounts. Use of foreign keys against the line item table to enforce an eventual running total of 0 Use of constraint triggers in PostgreSQL Forcing all validation here solely through the app logic. My concerns are that #1 is pretty limiting and very hard to audit internally. It's not programmer transparent and so it strikes me as being difficult to work with in the future. The second strikes me as being very complex and required a series of contraints and foreign keys against self to make work, and therefore it strikes me as complex, hard to sort out at least in my mind, and thus hard to work with. The fourth could be done as we force all access through stored procedures anyway and this is the most common solution (have the app total things up and throw an error otherwise). However, I think proof that a constraint is followed is superior to test cases, and so the question becomes whether this in fact generates insert anomilies rather than solving them. If this is a solved problem it isn't the case that everyone agrees on the solution....

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• ROracle support for TimesTen In-Memory Database

  - by Sherry LaMonica

  Today's guest post comes from Jason Feldhaus, a Consulting Member of Technical Staff in the TimesTen Database organization at Oracle.  He shares with us a sample session using ROracle with the TimesTen In-Memory database.  Beginning in version 1.1-4, ROracle includes support for the Oracle Times Ten In-Memory Database, version 11.2.2. TimesTen is a relational database providing very fast and high throughput through its memory-centric architecture.  TimesTen is designed for low latency, high-volume data, and event and transaction management. A TimesTen database resides entirely in memory, so no disk I/O is required for transactions and query operations. TimesTen is used in applications requiring very fast and predictable response time, such as real-time financial services trading applications and large web applications. TimesTen can be used as the database of record or as a relational cache database to Oracle Database. ROracle provides an interface between R and the database, providing the rich functionality of the R statistical programming environment using the SQL query language. ROracle uses the OCI libraries to handle database connections, providing much better performance than standard ODBC.The latest ROracle enhancements include: Support for Oracle TimesTen In-Memory Database Support for Date-Time using R's POSIXct/POSIXlt data types RAW, BLOB and BFILE data type support Option to specify number of rows per fetch operation Option to prefetch LOB data Break support using Ctrl-C Statement caching support Times Ten 11.2.2 contains enhanced support for analytics workloads and complex queries: Analytic functions: AVG, SUM, COUNT, MAX, MIN, DENSE_RANK, RANK, ROW_NUMBER, FIRST_VALUE and LAST_VALUE Analytic clauses: OVER PARTITION BY and OVER ORDER BY Multidimensional grouping operators: Grouping clauses: GROUP BY CUBE, GROUP BY ROLLUP, GROUP BY GROUPING SETS Grouping functions: GROUP, GROUPING_ID, GROUP_ID WITH clause, which allows repeated references to a named subquery block Aggregate expressions over DISTINCT expressions General expressions that return a character string in the source or a pattern within the LIKE predicate Ability to order nulls first or last in a sort result (NULLS FIRST or NULLS LAST in the ORDER BY clause) Note: Some functionality is only available with Oracle Exalytics, refer to the TimesTen product licensing document for details. Connecting to TimesTen is easy with ROracle. Simply install and load the ROracle package and load the driver. > install.packages("ROracle") > library(ROracle) Loading required package: DBI > drv <- dbDriver("Oracle") Once the ROracle package is installed, create a database connection object and connect to a TimesTen direct driver DSN as the OS user. > conn <- dbConnect(drv, username ="", password="", dbname = "localhost/SampleDb_1122:timesten_direct") You have the option to report the server type - Oracle or TimesTen? > print (paste ("Server type =", dbGetInfo (conn)$serverType)) [1] "Server type = TimesTen IMDB" To create tables in the database using R data frame objects, use the function dbWriteTable. In the following example we write the built-in iris data frame to TimesTen. The iris data set is a small example data set containing 150 rows and 5 columns. We include it here not to highlight performance, but so users can easily run this example in their R session. > dbWriteTable (conn, "IRIS", iris, overwrite=TRUE, ora.number=FALSE) [1] TRUE Verify that the newly created IRIS table is available in the database. To list the available tables and table columns in the database, use dbListTables and dbListFields, respectively. > dbListTables (conn) [1] "IRIS" > dbListFields (conn, "IRIS") [1] "SEPAL.LENGTH" "SEPAL.WIDTH" "PETAL.LENGTH" "PETAL.WIDTH" "SPECIES" To retrieve a summary of the data from the database we need to save the results to a local object. The following call saves the results of the query as a local R object, iris.summary. The ROracle function dbGetQuery is used to execute an arbitrary SQL statement against the database. When connected to TimesTen, the SQL statement is processed completely within main memory for the fastest response time. > iris.summary <- dbGetQuery(conn, 'SELECT SPECIES, AVG ("SEPAL.LENGTH") AS AVG_SLENGTH, AVG ("SEPAL.WIDTH") AS AVG_SWIDTH, AVG ("PETAL.LENGTH") AS AVG_PLENGTH, AVG ("PETAL.WIDTH") AS AVG_PWIDTH FROM IRIS GROUP BY ROLLUP (SPECIES)') > iris.summary SPECIES AVG_SLENGTH AVG_SWIDTH AVG_PLENGTH AVG_PWIDTH 1 setosa 5.006000 3.428000 1.462 0.246000 2 versicolor 5.936000 2.770000 4.260 1.326000 3 virginica 6.588000 2.974000 5.552 2.026000 4 <NA> 5.843333 3.057333 3.758 1.199333 Finally, disconnect from the TimesTen Database. > dbCommit (conn) [1] TRUE > dbDisconnect (conn) [1] TRUE We encourage you download Oracle software for evaluation from the Oracle Technology Network. See these links for our software: Times Ten In-Memory Database,  ROracle.  As always, we welcome comments and questions on the TimesTen and  Oracle R technical forums.

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• jQuery Templates, Data Link

  - by Renso

  Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Query Templates, Data Link, and Globalization I am sure you must have read Scott Guthrie’s blog post about jQuery support and officially supporting jQuery's templating, data linking and globalization, if not here it is: jQuery Templating Since we are an open source shop and use jQuery and jQuery plugins extensively to say the least, decided to look into the templating a bit and see what data linking is all about. For those not familiar with those terms here is the summary, plenty of material out there on what it is, but here is what in my experience it means: jQuery Templating: A templating engine that allows you to specify a client-side template where you indicate which properties/tags you want dynamically updated. You in a sense specify which parts of the html is dynamic and since it is pluggable you are able to use tools data jQuery data linking and others to let it sync up your template with data. What makes it more powerful is that you can easily work with rows of data, adding and removing rows. Once the template has been generated, which you do dynamically on a client-side event, you then append/inject the resulting template somewhere in your DOM, like for example you would get a JSON object from the database, map it to your template, it populates the template with your data in the indicated places, and then let’s say for example append it to a row in a table. I have not found it that useful for lets say a single record of data since you could easily just get a partial view from the server via an html type ajax call. It really shines when you dynamically add/remove rows from a list in the DOM. I have not found an alternative that meets the functionality of the jQuery template and helps of course that Microsoft officially supports it. In future versions of the jQuery plug-in it may even ship as part of the standard jQuery library and with future versions of Visual Studio. jQuery Data Linking: In short I was fascinated by it initially by how with one line of code I can sync up my JSON object with my form elements. That's where my enthusiasm stopped. It was one-line to let is deal with syncing up your form with your JSON object, but it is not bidirectional as they state and I tried all the work arounds they suggested and none of them work. The problem is that when you update your JSON object it DOES NOT sync it up with your form. In an example, accounts are being edited client side by selecting the account from a list by clicking on the row, it then fetches the entire account JSON object via ajax json-type call and then refreshes the form with the account’s details from the new JSON object. What is the use of syncing up my JSON with the form if I still have to programmatically sync up my new JSON object with each DOM property?! So you may ask: “what is the alternative”? Good question and the same one I was pondering, maybe I can just use it for keeping my from n sync with my JSON object so I can post that JSON object back to the server and update my database. That’s when I discovered Knockout: Knockout It addresses the issues mentioned above and also supports event handling through the observer pattern. Not wanting to go into detail here, Steve Sanderson, the creator of Knockout, has already done a terrific job of that, thanks Steve for a great plug-in! Best of all it integrates perfectly with the jQuery Templating engine as well. I have not found an alternative to this plugin that supports the depth and width of functionality and would recommend it to anyone. The only drawback is the embedded html attributes (data-bind=””) tags that you have to add to the HTML, in my opinion tying your behavior to your HTML, where I like to separate behavior from HTML as well as CSS, so the HTML is purely to define content, not styling or behavior. But there are plusses to this as well and also a nifty work around to this that I will just shortly mention here with an example. Instead of data binding an html tag with knockout event handling like so:  <%=Html.TextBox("PrepayDiscount", String.Empty, new { @class = "number" })%>   Do: <%=Html.DataBoundTextBox("PrepayDiscount", String.Empty, new { @class = "number" })%>   The html extension above then takes care of the internals and you could then swap Knockout for something else if you want to inside the extension and keep the HTML plugin agnostic. Here is what the extension looks like, you can easily build a whole library to support all kinds of data binding options from this:      public static class HtmlExtensions       {         public static MvcHtmlString DataBoundTextBox(this HtmlHelper helper, string name, object value, object htmlAttributes)         {             var dic = new RouteValueDictionary(htmlAttributes);             dic.Add("data-bind", String.Format("value: {0}", name));             return helper.TextBox(name, value, dic);         }       }   Hope this helps in making a decision when and where to consider jQuery templating, data linking and Knockout.

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• Oracle NoSQL Database Exceeds 1 Million Mixed YCSB Ops/Sec

  - by Charles Lamb

  We ran a set of YCSB performance tests on Oracle NoSQL Database using SSD cards and Intel Xeon E5-2690 CPUs with the goal of achieving 1M mixed ops/sec on a 95% read / 5% update workload. We used the standard YCSB parameters: 13 byte keys and 1KB data size (1,102 bytes after serialization). The maximum database size was 2 billion records, or approximately 2 TB of data. We sized the shards to ensure that this was not an "in-memory" test (i.e. the data portion of the B-Trees did not fit into memory). All updates were durable and used the "simple majority" replica ack policy, effectively 'committing to the network'. All read operations used the Consistency.NONE_REQUIRED parameter allowing reads to be performed on any replica. In the past we have achieved 100K ops/sec using SSD cards on a single shard cluster (replication factor 3) so for this test we used 10 shards on 15 Storage Nodes with each SN carrying 2 Rep Nodes and each RN assigned to its own SSD card. After correcting a scaling problem in YCSB, we blew past the 1M ops/sec mark with 8 shards and proceeded to hit 1.2M ops/sec with 10 shards.  Hardware Configuration We used 15 servers, each configured with two 335 GB SSD cards. We did not have homogeneous CPUs across all 15 servers available to us so 12 of the 15 were Xeon E5-2690, 2.9 GHz, 2 sockets, 32 threads, 193 GB RAM, and the other 3 were Xeon E5-2680, 2.7 GHz, 2 sockets, 32 threads, 193 GB RAM.  There might have been some upside in having all 15 machines configured with the faster CPU, but since CPU was not the limiting factor we don't believe the improvement would be significant. The client machines were Xeon X5670, 2.93 GHz, 2 sockets, 24 threads, 96 GB RAM. Although the clients had 96 GB of RAM, neither the NoSQL Database or YCSB clients require anywhere near that amount of memory and the test could have just easily been run with much less. Networking was all 10GigE. YCSB Scaling Problem We made three modifications to the YCSB benchmark. The first was to allow the test to accommodate more than 2 billion records (effectively int's vs long's). To keep the key size constant, we changed the code to use base 32 for the user ids. The second change involved to the way we run the YCSB client in order to make the test itself horizontally scalable.The basic problem has to do with the way the YCSB test creates its Zipfian distribution of keys which is intended to model "real" loads by generating clusters of key collisions. Unfortunately, the percentage of collisions on the most contentious keys remains the same even as the number of keys in the database increases. As we scale up the load, the number of collisions on those keys increases as well, eventually exceeding the capacity of the single server used for a given key.This is not a workload that is realistic or amenable to horizontal scaling. YCSB does provide alternate key distribution algorithms so this is not a shortcoming of YCSB in general. We decided that a better model would be for the key collisions to be limited to a given YCSB client process. That way, as additional YCSB client processes (i.e. additional load) are added, they each maintain the same number of collisions they encounter themselves, but do not increase the number of collisions on a single key in the entire store. We added client processes proportionally to the number of records in the database (and therefore the number of shards). This change to the use of YCSB better models a use case where new groups of users are likely to access either just their own entries, or entries within their own subgroups, rather than all users showing the same interest in a single global collection of keys. If an application finds every user having the same likelihood of wanting to modify a single global key, that application has no real hope of getting horizontal scaling. Finally, we used read/modify/write (also known as "Compare And Set") style updates during the mixed phase. This uses versioned operations to make sure that no updates are lost. This mode of operation provides better application behavior than the way we have typically run YCSB in the past, and is only practical at scale because we eliminated the shared key collision hotspots.It is also a more realistic testing scenario. To reiterate, all updates used a simple majority replica ack policy making them durable. Scalability Results In the table below, the "KVS Size" column is the number of records with the number of shards and the replication factor. Hence, the first row indicates 400m total records in the NoSQL Database (KV Store), 2 shards, and a replication factor of 3. The "Clients" column indicates the number of YCSB client processes. "Threads" is the number of threads per process with the total number of threads. Hence, 90 threads per YCSB process for a total of 360 threads. The client processes were distributed across 10 client machines. Shards KVS Size Clients Mixed (records) Threads OverallThroughput(ops/sec) Read Latencyav/95%/99%(ms) Write Latencyav/95%/99%(ms) 2 400m(2x3) 4 90(360) 302,152 0.76/1/3 3.08/8/35 4 800m(4x3) 8 90(720) 558,569 0.79/1/4 3.82/16/45 8 1600m(8x3) 16 90(1440) 1,028,868 0.85/2/5 4.29/21/51 10 2000m(10x3) 20 90(1800) 1,244,550 0.88/2/6 4.47/23/53

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• How can I set my screen resolution to match my TV?

  - by Scott Severance

  I have a computer in my classroom that's connected to an LG smart TV (that's actually not so smart. I wouldn't recommend buying one.). For the touch interface, the TV wants a resolution of 1920x1080 at 60Hz. However, I can't seem to set the computer to that resolution. The display settings only offer 1024x768 and 640x480. The computer dual boots with Windows XP, where widescreen options are available in approximately the required size, but the exact resolution -- or even aspect ratio-- isn't available in XP either. I tried the following command: xrandr -s 1920x1080 -r 60 The response was: Size 1920x1080 not found in available modes Back in the old days, the solution would be to edit xorg.conf. However, since that file no longer exists, and I haven't found up-to-date info, I don't know what else to do. If it helps, this machine will never be connected to a different display, so resolution flexibility isn't important. Here's the output of lshw: *-display:0 description: VGA compatible controller product: 4 Series Chipset Integrated Graphics Controller vendor: Intel Corporation physical id: 2 bus info: pci@0000:00:02.0 version: 03 width: 64 bits clock: 33MHz capabilities: vga_controller bus_master cap_list rom configuration: driver=i915 latency=0 resources: irq:42 memory:fe800000-febfffff memory:d0000000-dfffffff ioport:ecd8(size=8) *-display:1 UNCLAIMED description: Display controller product: 4 Series Chipset Integrated Graphics Controller vendor: Intel Corporation physical id: 2.1 bus info: pci@0000:00:02.1 version: 03 width: 64 bits clock: 33MHz According to the system settings, my graphics driver is unknown and my "experience" is standard. This is 64-bit Ubuntu 12.04 (Precise) Note: There are a number of similar questions to this one, but they didn't include any answers that helped me. Update After posting this question, I noticed one in the sidebar that I hadn't found through search but which appeared to contain the answer. Based on that question, I created the /etc/X11/xorg.conf file below: Section "ServerLayout" Identifier "X.org Configured" Screen 0 "Screen0" 0 0 InputDevice "Mouse0" "CorePointer" InputDevice "Keyboard0" "CoreKeyboard" EndSection Section "Files" ModulePath "/usr/lib/xorg/modules" FontPath "/usr/share/fonts/X11/misc" FontPath "/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType" FontPath "built-ins" EndSection Section "Module" Load "glx" Load "dri2" Load "dbe" Load "dri" Load "record" Load "extmod" EndSection Section "InputDevice" Identifier "Keyboard0" Driver "kbd" EndSection Section "InputDevice" Identifier "Mouse0" Driver "mouse" Option "Protocol" "auto" Option "Device" "/dev/input/mice" Option "ZAxisMapping" "4 5 6 7" EndSection Section "Monitor" Identifier "Monitor0" VendorName "LG" ModelName "Smart TV" EndSection Section "Device" ### Available Driver options are:- ### Values: <i>: integer, <f>: float, <bool>: "True"/"False", ### <string>: "String", <freq>: "<f> Hz/kHz/MHz", ### <percent>: "<f>%" ### [arg]: arg optional #Option "DRI" # [<bool>] #Option "ColorKey" # <i> #Option "VideoKey" # <i> #Option "FallbackDebug" # [<bool>] #Option "Tiling" # [<bool>] #Option "LinearFramebuffer" # [<bool>] #Option "Shadow" # [<bool>] #Option "SwapbuffersWait" # [<bool>] #Option "TripleBuffer" # [<bool>] #Option "XvMC" # [<bool>] #Option "XvPreferOverlay" # [<bool>] #Option "DebugFlushBatches" # [<bool>] #Option "DebugFlushCaches" # [<bool>] #Option "DebugWait" # [<bool>] #Option "HotPlug" # [<bool>] #Option "RelaxedFencing" # [<bool>] Identifier "Card0" Driver "intel" BusID "PCI:0:2:0" EndSection Section "Screen" Identifier "Screen0" Device "Card0" Monitor "Monitor0" DefaultDepth 24 #SubSection "Display" # Viewport 0 0 # Depth 1 #EndSubSection #SubSection "Display" # Viewport 0 0 # Depth 4 #EndSubSection #SubSection "Display" # Viewport 0 0 # Depth 8 #EndSubSection #SubSection "Display" # Viewport 0 0 # Depth 15 #EndSubSection #SubSection "Display" # Viewport 0 0 # Depth 16 #EndSubSection SubSection "Display" Viewport 0 0 Depth 24 Modes "1024x768" "1920x1080" EndSubSection EndSection According to /var/log/Xorg.0.log, my settings aren't being applied. In fact, I wonder if the config file is even being read. [ 1209.083] (**) intel(0): Depth 24, (--) framebuffer bpp 32 [ 1209.084] (==) intel(0): RGB weight 888 [ 1209.084] (==) intel(0): Default visual is TrueColor [ 1209.084] (II) intel(0): Integrated Graphics Chipset: Intel(R) G41 [ 1209.084] (--) intel(0): Chipset: "G41" [ 1209.084] (**) intel(0): Relaxed fencing enabled [ 1209.084] (**) intel(0): Wait on SwapBuffers? enabled [ 1209.084] (**) intel(0): Triple buffering? enabled [ 1209.084] (**) intel(0): Framebuffer tiled [ 1209.084] (**) intel(0): Pixmaps tiled [ 1209.084] (**) intel(0): 3D buffers tiled [ 1209.084] (**) intel(0): SwapBuffers wait enabled [ 1209.084] (==) intel(0): video overlay key set to 0x101fe [ 1209.172] (II) intel(0): Output VGA1 using monitor section Monitor0 [ 1209.260] (II) intel(0): EDID for output VGA1 [ 1209.260] (II) intel(0): Printing probed modes for output VGA1 [ 1209.260] (II) intel(0): Modeline "1024x768"x60.0 65.00 1024 1048 1184 1344 768 771 777 806 -hsync -vsync (48.4 kHz) [ 1209.260] (II) intel(0): Modeline "800x600"x60.3 40.00 800 840 968 1056 600 601 605 628 +hsync +vsync (37.9 kHz) [ 1209.260] (II) intel(0): Modeline "800x600"x56.2 36.00 800 824 896 1024 600 601 603 625 +hsync +vsync (35.2 kHz) [ 1209.260] (II) intel(0): Modeline "848x480"x60.0 33.75 848 864 976 1088 480 486 494 517 +hsync +vsync (31.0 kHz) [ 1209.260] (II) intel(0): Modeline "640x480"x59.9 25.18 640 656 752 800 480 489 492 525 -hsync -vsync (31.5 kHz) [ 1209.260] (II) intel(0): Output VGA1 connected [ 1209.260] (II) intel(0): Using user preference for initial modes [ 1209.260] (II) intel(0): Output VGA1 using initial mode 1024x768 [ 1209.260] (II) intel(0): Using default gamma of (1.0, 1.0, 1.0) unless otherwise stated. [ 1209.260] (II) intel(0): Kernel page flipping support detected, enabling [ 1209.260] (==) intel(0): DPI set to (96, 96)

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• Webcor Builders Coordinates Construction Schedules and Mitigates Potential Delays More Efficiently with Integrated Project Management

  - by Sylvie MacKenzie, PMP

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} With more than 40 years of commercial construction experience, Webcor Builders is a leading builder of distinguished, high-profile projects, including high-rise condominiums and hotels, laboratories, healthcare centers, and public works projects. Webcor is also known for its award-winning concrete, interior construction, historic restoration, and seismic renovation work. The company has completed more than 50 million square feet of projects to date. Considering the variety and complexity of the construction projects Webcor undertakes, an integrated project management solution is critical to ensuring optimal efficiency and completing client projects on time and on budget. The company previously used a number of scheduling systems for its various building projects. These packages provided different levels of schedule detail and required schedulers, engineers, and other employees to learn multiple systems. From an IT cost and complexity perspective, the company had to manage multiple scheduling systems and pay for multiple sets of licenses. The company looked to standardize on an enterprise project management system, and selected Oracle’s Primavera P6 Enterprise Project Portfolio Management. Webcor uses the solution’s advanced capabilities to schedule complex projects, analyze delays, model and propose multiple scenarios to demonstrate and mitigate delays and cost overruns, and process that information efficiently to deliver the scheduling precision that public and private projects require. In fact, the solution was instrumental in helping the company’s expansion into public sector projects during the recent economic downturn, and with Primavera P6 in place, it can deliver the precise schedule reporting required for large public projects. With Primavera P6 in place, the company could deliver the precise scheduling and milestone reporting capabilities required for large public projects. The solution is in managing the high-profile University of California – Berkeley Memorial Stadium project. Webcor was hired as construction manager and general contractor for the stadium renovation project, which is a fast-paced project located near the seismically active Hayward Fault Zone. Due to the University of California’s football schedule, meeting the Universities deadline for the coming season placed Webcor in a situation where risk awareness and early warnings of issues would be paramount. Webcor and the extended project team needed a solution that could instantly analyze alternate scenarios to mitigate potential delays; Primavera would deliver those answers.The team would also need to enable multiple stakeholders to use an internet-based platform to access the schedule from various locations, and model complicated sequencing requirements where swift decisions would be made to keep the project on track. The schedule is an integral part of Webcor’s construction management process for the stadium project. Rather than providing the client with the industry-standard monthly update, Webcor updates the critical path method (CPM) schedule on a weekly basis. The project team also reviews the schedule and updates weekly to confirm that progress and forecasted performance are accurate. Hired by the University for their ability to deliver in high risk environments The Webcor team was hit recently with a design supplement that could have added up to 70 days to the project. Using Oracle Primavera P6 the team sprung into action analyzing multiple “what if” scenarios to review mitigation means and methods.  Determined to make sure the Bears could take the field in the coming season the project team nearly eliminated the impact with their creative analysis in working the schedule. The total time from the issuance of the final design supplement to an agreed mitigation response was less than one week; leveraging the Oracle Primavera solution Webcor was able to deliver superior customer value With the ability to efficiently manage projects and schedules, Webcor can ensure it completes its projects on time and on budget, as well as inform clients about what changes to plans will mean in terms of delays and additional costs. Read the complete customer case study at :  http://www.oracle.com/us/corporate/customers/customersearch/webcor-builders-1-primavera-ss-1639886.html

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• #OOW 2012 : IaaS, Private Cloud, Multitenant Database, and X3H2M2

  - by Eric Bezille

  The title of this post is a summary of the 4 announcements made by Larry Ellison today, during the opening session of Oracle Open World 2012... To know what's behind X3H2M2, you will have to wait a little, as I will go in order, beginning with the IaaS - Infrastructure as a Service - announcement. Oracle IaaS goes Public... and Private... Starting in 2004 with Fusion development, Oracle Cloud was launch last year to provide not only SaaS Application, based on standard development, but also the underlying PaaS, required to build the specifics, and required interconnections between applications, in and outside of the Cloud. Still, to cover the end-to-end Cloud  Services spectrum, we had to provide an Infrastructure as a Service, leveraging our Servers, Storage, OS, and Virtualization Technologies, all "Engineered Together". This Cloud Infrastructure, was already available for our customers to build rapidly their own Private Cloud either on SPARC/Solaris or x86/Linux... The second announcement made today bring that proposition a big step further : for cautious customers (like Banks, or sensible industries) who would like to benefits from the Cloud value of "as a Service", but don't want their Data out in the Cloud... We propose to them to operate the same systems, Exadata, Exalogic & SuperCluster, that are providing our Public Cloud Infrastructure, behind their firewall, in a Private Cloud model. Oracle 12c Multitenant Database This is also a major announcement made today, on what's coming with Oracle Database 12c : the ability to consolidate multiple databases with no extra additional  cost especially in terms of memory needed on the server node, which is often THE consolidation limiting factor. The principle could be compare to Solaris Zones, where, you will have a Database Container, who is "owning" the memory and Database background processes, and "Pluggable" Database in this Database Container. This particular feature is a strong compelling event to evaluate rapidly Oracle Database 12c once it will be available, as this is major step forward into true Database consolidation with Multitenancy on a shared (optimized) infrastructure. X3H2M2, enabling the new Exadata X3 in-Memory Database Here we are :  X3H2M2 stands for X3 (the new version of Exadata announced also today) Heuristic Hierarchical Mass Memory, providing the capability to keep most if not all the Data in the memory cache hierarchy. Of course, this is the major software enhancement of the new X3 Exadata machine, but as this is a software, our current customers would be able to benefit from it on their existing systems by upgrading to the new release. But that' not the only thing that we did with X3, at the same time we have upgraded everything : the CPUs, adding more cores per server node (16 vs. 12, with the arrival of Intel E5 / Sandy Bridge), the memory with 512GB memory as well per node,  and the new Flash Fire card, bringing now up to 22 TB of Flash cache. All of this 4TB of RAM + 22TB of Flash being use cleverly not only for read but also for write by the X3H2M2 algorithm... making a very big difference compare to traditional storage flash extension. But what does those extra performances brings to you on an already very efficient system: double your performances compare to the fastest storage array on the market today (including flash) and divide you storage price x10 at the same time... Something to consider closely this days... Especially that we also announced the availability of a new Exadata X3-2 8th rack : a good starting point. As you have seen a major opening for this year again with true innovation. But that was not the only thing that we saw today, as before Larry's talk, Fujitsu did introduce more in deep the up coming new SPARC processor, that they are co-developing with us. And as such Andrew Mendelsohn - Senior Vice President Database Server Technologies came on stage to explain that the next step after I/O optimization for Database with Exadata, was to accelerate the Database at execution level by bringing functions in the SPARC processor silicium. All in all, to process more and more Data... The big theme of the day... and of the Oracle User Groups Conferences that were also happening today and where I had the opportunity to attend some interesting sessions on practical use cases of Big Data one in Finances and Fraud profiling and the other one on practical deployment of Oracle Exalytics for Data Analytics. In conclusion, one picture to try to size Oracle Open World ... and you can understand why, with such a rich content... and this only the first day !

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• Access Control Service v2: Registering Web Identities in your Applications [concepts]

  - by Your DisplayName here!

  ACS v2 support two fundamental types of client identities– I like to call them “enterprise identities” (WS-*) and “web identities” (Google, LiveID, OpenId in general…). I also see two different “mind sets” when it comes to application design using the above identity types: Enterprise identities – often the fact that a client can present a token from a trusted identity provider means he is a legitimate user of the application. Trust relationships and authorization details have been negotiated out of band (often on paper). Web identities – the fact that a user can authenticate with Google et al does not necessarily mean he is a legitimate (or registered) user of an application. Typically additional steps are necessary (like filling out a form, email confirmation etc). Sometimes also a mixture of both approaches exist, for the sake of this post, I will focus on the web identity case. I got a number of questions how to implement the web identity scenario and after some conversations it turns out it is the old authentication vs. authorization problem that gets in the way. Many people use the IsAuthenticated property on IIdentity to make security decisions in their applications (or deny user=”?” in ASP.NET terms). That’s a very natural thing to do, because authentication was done inside the application and we knew exactly when the IsAuthenticated condition is true. Been there, done that. Guilty ;) The fundamental difference between these “old style” apps and federation is, that authentication is not done by the application anymore. It is done by a third party service, and in the case of web identity providers, in services that are not under our control (nor do we have a formal business relationship with these providers). Now the issue is, when you switch to ACS, and someone with a Google account authenticates, indeed IsAuthenticated is true – because that’s what he is! This does not mean, that he is also authorized to use the application. It just proves he was able to authenticate with Google. Now this obviously leads to confusion. How can we solve that? Easy answer: We have to deal with authentication and authorization separately. Job done ;) For many application types I see this general approach: Application uses ACS for authentication (maybe both enterprise and web identities, we focus on web identities but you could easily have a dual approach here) Application offers to authenticate (or sign in) via web identity accounts like LiveID, Google, Facebook etc. Application also maintains a database of its “own” users. Typically you want to store additional information about the user In such an application type it is important to have a unique identifier for your users (think the primary key of your user database). What would that be? Most web identity provider (and all the standard ACS v2 supported ones) emit a NameIdentifier claim. This is a stable ID for the client (scoped to the relying party – more on that later). Furthermore ACS emits a claims identifying the identity provider (like the original issuer concept in WIF). When you combine these two values together, you can be sure to have a unique identifier for the user, e.g.: Facebook-134952459903700\799880347 You can now check on incoming calls, if the user is already registered and if yes, swap the ACS claims with claims coming from your user database. One claims would maybe be a role like “Registered User” which can then be easily used to do authorization checks in the application. The WIF claims authentication manager is a perfect place to do the claims transformation. If the user is not registered, show a register form. Maybe you can use some claims from the identity provider to pre-fill form fields. (see here where I show how to use the Facebook API to fetch additional user properties). After successful registration (which may include other mechanisms like a confirmation email), flip the bit in your database to make the web identity a registered user. This is all very theoretical. In the next post I will show some code and provide a download link for the complete sample. More on NameIdentifier Identity providers “guarantee” that the name identifier for a given user in your application will always be the same. But different applications (in the case of ACS – different ACS namespaces) will see different name identifiers. This is by design to protect the privacy of users because identical name identifiers could be used to create “profiles” of some sort for that user. In technical terms they create the name identifier approximately like this: name identifier = Hash((Provider Internal User ID) + (Relying Party Address)) Why is this important to know? Well – when you change the name of your ACS namespace, the name identifiers will change as well and you will will lose your “connection” to your existing users. Oh an btw – never use any other claims (like email address or name) to form a unique ID – these can often be changed by users.

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• Common reasons for the &lsquo;Sys is undefined&rsquo; error in ASP.NET Ajax applications

    In this blog I will try to summarize the most common reasons for getting the famous 'Sys is undefined' error when running an Ajax enabled web site or application (there are almost one milion results on Google for that phrase). Where does it come from? In every Ajax web pages source you will see a code like this: <script type="text/javascript"> //<![CDATA[ Sys.WebForms.PageRequestManager._initialize('ScriptManager1', document.getElementById('form1')); Sys.WebForms.PageRequestManager.getInstance()._updateControls([], [], [], 90); //]]> </script>   This is the initialization script of the ScriptManager. So, if for some reason the Sys namespace is not available when the code executes you get the Sys is undefined error. Here are the most common reasons and solutions for that problem:   1. The error occurs when you have added a control from RadControls for ASP.NET AJAX, but your application is not configured to use ASP.NET AJAX. For example, in VS 2005 you created a new Blank Site instead of a new Ajax-Enabled Web Site and the Sys is undefined message pops up. To fix it you need to follow the steps described at Configuring ASP.NET Ajax article (check the topic called Adding ASP.NET AJAX Configuration Elements to an Existing Web Site) or simply create the Ajax-Enabled Web Site. You can also check my other blog post on the matter: Visual Studio 2008: Where is the new ASP.NET Ajax-Enabled Web Site template?   2. Authentication - as the website denies access to all pages to unauthorized users, access to the Telerik.Web.UI.WebResource.axd handler is unauthorized (this is the default handler of RadScriptManager). This causes the handler to serve the content of the login page instead of the combined scripts, hence the error. To solve it - add a <location> section to the application configuration file to allow access to Telerik.Web.UI.WebResource.axd to all users, like: <configuration> ... <location path="Telerik.Web.UI.WebResource.axd"> <system.web> <authorization> <allow users="*"/> </authorization> </system.web> </location> ... </configuration>   Note that the access to the standard ScriptResource.axd and WebResource.axd is automatically allowed for all users (authenticated and unauthenticated), so if you use the ScriptManager instead of RadScriptManager - you will not face this problem. The authentication problem does not manifest when you disable script combining or use the CDN. Adding the above configuration section will make it work with RadScriptManagers combined script.   3. The IE6 browser fails to load the compressed script. The problem does not appear in any other browser. There is a well known bug in the older versions of IE6 which lose the first 2,048 bytes of data that are sent back from a Web server that uses HTTP compression. Latest versions of RadScriptManager does not compress the output at all if the client is IE6, but in the previous versions you need to manually disable the output compression to prevent the error. So, if you get the Sys is undefined error in IE6 - update to the latest version of RadControls or simply disable the output compression.   4. Requests to the *.axd files returns Error Code 404 - Not Found. This could  be fixed easily: Check in the IIS management console that the .axd extension (the default HTTP handler extension) is allowed:     Also check if the Verify if file exists checkbox is unchecked (click on the Edit button appearing in the previous screenshot to check). More information can be found in our troubleshooting article and from the ASP.NET QA team blog post   5. The virtual directory in IIS is not marked as Web Application. Converting it to Web Application should fix the problem.   6. Check for the <xhtmlConformance mode="Legacy"/> option in your web.config and remove it. It would be rather rare to become a victim of this exact case, but still have it in mind. Scott Guthrie describes it in more details   In the above points I mentioned several times the terms web resources, javascript output, compressed script. If you want to find out more about these please see the Web Resources Demystified series of my friend and colleague Atanas Korchev   I hope that one of the above solutions will help you get rid of the Sys is undefined error.   Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• Null Values And The T-SQL IN Operator

  - by Jesse

  I came across some unexpected behavior while troubleshooting a failing test the other day that took me long enough to figure out that I thought it was worth sharing here. I finally traced the failing test back to a SELECT statement in a stored procedure that was using the IN t-sql operator to exclude a certain set of values. Here’s a very simple example table to illustrate the issue: Customers CustomerId INT, NOT NULL, Primary Key CustomerName nvarchar(100) NOT NULL SalesRegionId INT NULL   The ‘SalesRegionId’ column contains a number representing the sales region that the customer belongs to. This column is nullable because new customers get created all the time but assigning them to sales regions is a process that is handled by a regional manager on a periodic basis. For the purposes of this example, the Customers table currently has the following rows: CustomerId CustomerName SalesRegionId 1 Customer A 1 2 Customer B NULL 3 Customer C 4 4 Customer D 2 5 Customer E 3   How could we write a query against this table for all customers that are NOT in sales regions 2 or 4? You might try something like this: 1: SELECT 2: CustomerId, 3: CustomerName, 4: SalesRegionId 5: FROM Customers 6: WHERE SalesRegionId NOT IN (2,4)   Will this work? In short, no; at least not in the way that you might expect. Here’s what this query will return given the example data we’re working with: CustomerId CustomerName SalesRegionId 1 Customer A 1 5 Customer E 5   I was expecting that this query would also return ‘Customer B’, since that customer has a NULL SalesRegionId. In my mind, having a customer with no sales region should be included in a set of customers that are not in sales regions 2 or 4.When I first started troubleshooting my issue I made note of the fact that this query should probably be re-written without the NOT IN clause, but I didn’t suspect that the NOT IN clause was actually the source of the issue. This particular query was only one minor piece in a much larger process that was being exercised via an automated integration test and I simply made a poor assumption that the NOT IN would work the way that I thought it should. So why doesn’t this work the way that I thought it should? From the MSDN documentation on the t-sql IN operator: If the value of test_expression is equal to any value returned by subquery or is equal to any expression from the comma-separated list, the result value is TRUE; otherwise, the result value is FALSE. Using NOT IN negates the subquery value or expression. The key phrase out of that quote is, “… is equal to any expression from the comma-separated list…”. The NULL SalesRegionId isn’t included in the NOT IN because of how NULL values are handled in equality comparisons. From the MSDN documentation on ANSI_NULLS: The SQL-92 standard requires that an equals (=) or not equal to (<>) comparison against a null value evaluates to FALSE. When SET ANSI_NULLS is ON, a SELECT statement using WHERE column_name = NULL returns zero rows even if there are null values in column_name. A SELECT statement using WHERE column_name <> NULL returns zero rows even if there are nonnull values in column_name. In fact, the MSDN documentation on the IN operator includes the following blurb about using NULL values in IN sub-queries or expressions that are used with the IN operator: Any null values returned by subquery or expression that are compared to test_expression using IN or NOT IN return UNKNOWN. Using null values in together with IN or NOT IN can produce unexpected results. If I were to include a ‘SET ANSI_NULLS OFF’ command right above my SELECT statement I would get ‘Customer B’ returned in the results, but that’s definitely not the right way to deal with this. We could re-write the query to explicitly include the NULL value in the WHERE clause: 1: SELECT 2: CustomerId, 3: CustomerName, 4: SalesRegionId 5: FROM Customers 6: WHERE (SalesRegionId NOT IN (2,4) OR SalesRegionId IS NULL)   This query works and properly includes ‘Customer B’ in the results, but I ultimately opted to re-write the query using a LEFT OUTER JOIN against a table variable containing all of the values that I wanted to exclude because, in my case, there could potentially be several hundred values to be excluded. If we were to apply the same refactoring to our simple sales region example we’d end up with: 1: DECLARE @regionsToIgnore TABLE (IgnoredRegionId INT) 2: INSERT @regionsToIgnore values (2),(4) 3:  4: SELECT 5: c.CustomerId, 6: c.CustomerName, 7: c.SalesRegionId 8: FROM Customers c 9: LEFT OUTER JOIN @regionsToIgnore r ON r.IgnoredRegionId = c.SalesRegionId 10: WHERE r.IgnoredRegionId IS NULL By performing a LEFT OUTER JOIN from Customers to the @regionsToIgnore table variable we can simply exclude any rows where the IgnoredRegionId is null, as those represent customers that DO NOT appear in the ignored regions list. This approach will likely perform better if the number of sales regions to ignore gets very large and it also will correctly include any customers that do not yet have a sales region.

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• Right-Time Retail Part 2

  - by David Dorf

  This is part two of the three-part series. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Right-Time Integration Of course these real-time enabling technologies are only as good as the systems that utilize them, and it only takes one bottleneck to slow everyone else down. What good is an immediate stock-out notification if the supply chain can’t react until tomorrow? Since being formed in 2006, Oracle Retail has been not only adding more integrations between systems, but also modernizing integrations for appropriate speed. Notice I tossed in the word “appropriate.” Not everything needs to be real-time – again, we’re talking about Right-Time Retail. The speed of data capture, analysis, and execution must be synchronized or you’re wasting effort. Unfortunately, there isn’t an enterprise-wide dial that you can crank-up for your estate. You’ll need to improve things piecemeal, with people and processes as limiting factors while choosing the appropriate types of integrations. There are three integration styles we see in the retail industry. First is batch. I know, the word “batch” just sounds slow, but this pattern is less about velocity and more about volume. When there are large amounts of data to be moved, you’ll want to use batch processes. Our technology of choice here is Oracle Data Integrator (ODI), which provides a fast version of Extract-Transform-Load (ETL). Instead of the three-step process, the load and transform steps are combined to save time. ODI is a key technology for moving data into Retail Analytics where we can apply science. Performing analytics on each sale as it occurs doesn’t make any sense, so we batch up a statistically significant amount and submit all at once. The second style is fire-and-forget. For some types of data, we want the data to arrive ASAP but immediacy is not necessary. Speed is less important than guaranteed delivery, so we use message-oriented middleware available in both Weblogic and the Oracle database. For example, Point-of-Service transactions are queued for delivery to Central Office at corporate. If the network is offline, those transactions remain in the queue and will be delivered when the network returns. Transactions cannot be lost and they must be delivered in order. (Ever tried processing a return before the sale?) To enhance the standard queues, we offer the Retail Integration Bus (RIB) to help the management and monitoring of fire-and-forget messaging in the enterprise. The third style is request-response and is most commonly implemented as Web services. This is a synchronous message where the sender waits for a response. In this situation, the volume of data is small, guaranteed delivery is not necessary, but speed is very important. Examples include the website checking inventory, a price lookup, or processing a credit card authorization. The Oracle Service Bus (OSB) typically handles the routing of such messages, and we’ve enhanced its abilities with the Retail Service Backbone (RSB). To better understand these integration patterns and where they apply within the retail enterprise, we’re providing the Retail Reference Library (RRL) at no charge to Oracle Retail customers. The library is composed of a large number of industry business processes, including those necessary to support Commerce Anywhere, as well as detailed architectural diagrams. These diagrams allow implementers to understand the systems involved in integrations and the specific data payloads. Furthermore, with our upcoming release we’ll be providing a new tool called the Retail Integration Console (RIC) that allows IT to monitor and manage integrations from a single point. Using RIC, retailers can quickly discern where integration activity is occurring, volume statistics, average response times, and errors. The dashboards provide the ability to dive down into the architecture documentation to gather information all the way down to the specific payload. Retailers that want real-time integrations will also need real-time monitoring of those integrations to ensure service-level agreements are maintained. Part 3 looks at marketing.

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• ADF Reusable Artefacts

  - by Arda Eralp

  Primary reusable ADF Business Component: Entity Objects (EOs) View Objects (VOs) Application Modules (AMs) Framework Extensions Classes Primary reusable ADF Controller: Bounded Task Flows (BTFs) Task Flow Templates Primary reusable ADF Faces: Page Templates Skins Declarative Components Utility Classes Certain components will often be used more than once. Whether the reuse happens within the same application, or across different applications, it is often advantageous to package these reusable components into a library that can be shared between different developers, across different teams, and even across departments within an organization. In the world of Java object-oriented programming, reusing classes and objects is just standard procedure. With the introduction of the model-view-controller (MVC) architecture, applications can be further modularized into separate model, view, and controller layers. By separating the data (model and business services layers) from the presentation (view and controller layers), you ensure that changes to any one layer do not affect the integrity of the other layers. You can change business logic without having to change the UI, or redesign the web pages or front end without having to recode domain logic. Oracle ADF and JDeveloper support the MVC design pattern. When you create an application in JDeveloper, you can choose many application templates that automatically set up data model and user interface projects. Because the different MVC layers are decoupled from each other, development can proceed on different projects in parallel and with a certain amount of independence. ADF Library further extends this modularity of design by providing a convenient and practical way to create, deploy, and reuse high-level components. When you first design your application, you design it with component reusability in mind. If you created components that can be reused, you can package them into JAR files and add them to a reusable component repository. If you need a component, you may look into the repository for those components and then add them into your project or application. For example, you can create an application module for a domain and package it to be used as the data model project in several different applications. Or, if your application will be consuming components, you may be able to load a page template component from a repository of ADF Library JARs to create common look and feel pages. Then you can put your page flow together by stringing together several task flow components pulled from the library. An ADF Library JAR contains ADF components and does not, and cannot, contain other JARs. It should not be confused with the JDeveloper library, Java EE library, or Oracle WebLogic shared library. Reusable Component Description Data Control Any data control can be packaged into an ADF Library JAR. Some of the data controls supported by Oracle ADF include application modules, Enterprise JavaBeans, web services, URL services, JavaBeans, and placeholder data controls. Application Module When you are using ADF Business Components and you generate an application module, an associated application module data control is also generated. When you package an application module data control, you also package up the ADF Business Components associated with that application module. The relevant entity objects, view objects, and associations will be a part of the ADF Library JAR and available for reuse. Business Components Business components are the entity objects, view objects, and associations used in the ADF Business Components data model project. You can package business components by themselves or together with an application module. Task Flows & Task Flow Templates Task flows can be packaged into an ADF Library JAR for reuse. If you drop a bounded task flow that uses page fragments, JDeveloper adds a region to the page and binds it to the dropped task flow. ADF bounded task flows built using pages can be dropped onto pages. The drop will create a link to call the bounded task flow. A task flow call activity and control flow will automatically be added to the task flow, with the view activity referencing the page. If there is more than one existing task flow with a view activity referencing the page, it will prompt you to select the one to automatically add a task flow call activity and control flow. If an ADF task flow template was created in the same project as the task flow, the ADF task flow template will be included in the ADF Library JAR and will be reusable. Page Templates You can package a page template and its artifacts into an ADF Library JAR. If the template uses image files and they are included in a directory within your project, these files will also be available for the template during reuse. Declarative Components You can create declarative components and package them for reuse. The tag libraries associated with the component will be included and loaded into the consuming project. You can also package up projects that have several different reusable components if you expect that more than one component will be consumed. For example, you can create a project that has both an application module and a bounded task flow. When this ADF Library JAR file is consumed, the application will have both the application module and the task flow available for use. You can package multiple components into one JAR file, or you can package a single component into a JAR file. Oracle ADF and JDeveloper give you the option and flexibility to create reusable components that best suit you and your organization. You create a reusable component by using JDeveloper to package and deploy the project that contains the components into a ADF Library JAR file. You use the components by adding that JAR to the consuming project. At design time, the JAR is added to the consuming project's class path and so is available for reuse. At runtime, the reused component runs from the JAR file by reference.

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• Documentation Changes in Solaris 11.1

  - by alanc

  One of the first places you can see Solaris 11.1 changes are in the docs, which have now been posted in the Solaris 11.1 Library on docs.oracle.com. I spent a good deal of time reviewing documentation for this release, and thought some would be interesting to blog about, but didn't review all the changes (not by a long shot), and am not going to cover all the changes here, so there's plenty left for you to discover on your own. Just comparing the Solaris 11.1 Library list of docs against the Solaris 11 list will show a lot of reorganization and refactoring of the doc set, especially in the system administration guides. Hopefully the new break down will make it easier to get straight to the sections you need when a task is at hand. Packaging System Unfortunately, the excellent in-depth guide for how to build packages for the new Image Packaging System (IPS) in Solaris 11 wasn't done in time to make the initial Solaris 11 doc set. An interim version was published shortly after release, in PDF form on the OTN IPS page. For Solaris 11.1 it was included in the doc set, as Packaging and Delivering Software With the Image Packaging System in Oracle Solaris 11.1, so should be easier to find, and easier to share links to specific pages the HTML version. Beyond just how to build a package, it includes details on how Solaris is packaged, and how package updates work, which may be useful to all system administrators who deal with Solaris 11 upgrades & installations. The Adding and Updating Oracle Solaris 11.1 Software Packages was also extended, including new sections on Relaxing Version Constraints Specified by Incorporations and Locking Packages to a Specified Version that may be of interest to those who want to keep the Solaris 11 versions of certain packages when they upgrade, such as the couple of packages that had functionality removed by an (unusual for an update release) End of Feature process in the 11.1 release. Also added in this release is a document containing the lists of all the packages in each of the major package groups in Solaris 11.1 (solaris-desktop, solaris-large-server, and solaris-small-server). While you can simply get the contents of those groups from the package repository, either via the web interface or the pkg command line, the documentation puts them in handy tables for easier side-by-side comparison, or viewing the lists before you've installed the system to pick which one you want to initially install. X Window System We've not had good X11 coverage in the online Solaris docs in a while, mostly relying on the man pages, and upstream X.Org docs. In this release, we've integrated some X coverage into the Solaris 11.1 Desktop Adminstrator's Guide, including sections on installing fonts for fontconfig or legacy X11 clients, X server configuration, and setting up remote access via X11 or VNC. Of course we continue to work on improving the docs, including a lot of contributions to the upstream docs all OS'es share (more about that another time). Security One of the things Oracle likes to do for its products is to publish security guides for administrators & developers to know how to build systems that meet their security needs. For Solaris, we started this with Solaris 11, providing a guide for sysadmins to find where the security relevant configuration options were documented. The Solaris 11.1 Security Guidelines extend this to cover new security features, such as Address Space Layout Randomization (ASLR) and Read-Only Zones, as well as adding additional guidelines for existing features, such as how to limit the size of tmpfs filesystems, to avoid users driving the system into swap thrashing situations. For developers, the corresponding document is the Developer's Guide to Oracle Solaris 11 Security, which has been the source for years for documentation of security-relevant Solaris API's such as PAM, GSS-API, and the Solaris Cryptographic Framework. For Solaris 11.1, a new appendix was added to start providing Secure Coding Guidelines for Developers, leveraging the CERT Secure Coding Standards and OWASP guidelines to provide the base recommendations for common programming languages and their standard API's. Solaris specific secure programming guidance was added via links to other documentation in the product doc set. In parallel, we updated the Solaris C Libary Functions security considerations list with details of Solaris 11 enhancements such as FD_CLOEXEC flags, additional *at() functions, and new stdio functions such as asprintf() and getline(). A number of code examples throughout the Solaris 11.1 doc set were updated to follow these recommendations, changing unbounded strcpy() calls to strlcpy(), sprintf() to snprintf(), etc. so that developers following our examples start out with safer code. The Writing Device Drivers guide even had the appendix updated to list which of these utility functions, like snprintf() and strlcpy(), are now available via the Kernel DDI. Little Things Of course all the big new features got documented, and some major efforts were put into refactoring and renovation, but there were also a lot of smaller things that got fixed as well in the nearly a year between the Solaris 11 and 11.1 doc releases - again too many to list here, but a random sampling of the ones I know about & found interesting or useful: The Privileges section of the DTrace Guide now gives users a pointer to find out how to set up DTrace privileges for non-global zones and what limitations are in place there. A new section on Recommended iSCSI Configuration Practices was added to the iSCSI configuration section when it moved into the SAN Configuration and Multipathing administration guide. The Managing System Power Services section contains an expanded explanation of the various tunables for power management in Solaris 11.1. The sample dcmd sources in /usr/demo/mdb were updated to include ::help output, so that developers like myself who follow the examples don't forget to include it (until a helpful code reviewer pointed it out while reviewing the mdb module changes for Xorg 1.12). The README file in that directory was updated to show the correct paths for installing both kernel & userspace modules, including the 64-bit variants.

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• Oracle Cloud Applications: The Right Ingredients Baked In

  - by yaldahhakim

  v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Normal 0 false false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Oracle Cloud Applications: The Right Ingredients Baked In Eggs, flour, milk, and sugar. The magic happens when you mix these ingredients together. The same goes for the hottest technologies fast changing how IT impacts our organizations today: cloud, social, mobile, and big data. By themselves they’re pretty good; combining them with a great recipe is what unlocks real transformation power. Choosing the right cloud can be very similar to choosing the right cake. First consider comparing the core ingredients that go into baking a cake and the core design principles in building a cloud-based application. For instance, if flour is the base ingredient of a cake, then rich functionality that spans complete business processes is the base of an enterprise-grade cloud. Cloud computing is more than just consuming an "application as service", and having someone else manage it for you. Rather, the value of cloud is about making your business more agile in the marketplace, and shortening the time it takes to deliver and adopt new innovation. It’s also about improving not only the efficiency at which we communicate but the actual quality of the information shared as well. Data from different systems, like ingredients in a cake, must also be blended together effectively and evaluated through a consolidated lens. When this doesn’t happen, for instance when data in your sales cloud doesn't seamlessly connect with your order management and other “back office” applications, the speed and quality of information can decrease drastically. It’s like mixing ingredients in a strainer with a straw – you just can’t bring it all together without losing something. Mixing ingredients is similar to bringing clouds together, and co-existing cloud applications with traditional on premise applications. This is where a shared services  platform built on open standards and Service Oriented Architecture (SOA) is critical. It’s essentially a cloud recipe that calls for not only great ingredients, but also ingredients you can get locally or most likely already have in your kitchen (or IT shop.) Open standards is the best way to deliver a cost effective, durable application integration strategy – regardless of where your apps are deployed. It’s also the best way to build your own cloud applications, or extend the ones you consume from a third party. Just like using standard ingredients and tools you already have in your kitchen, a standards based cloud enables your IT resources to ensure a cloud works easily with other systems. Your IT staff can also make changes using tools they are already familiar with. Or even more ideal, enable business users to actually tailor their experience without having to call upon IT for help at all. This frees IT resources to focus more on developing new innovative services for the organization vs. run and maintain. Carrying the cake analogy forward, you need to add all the ingredients in before you bake it. The same is true with a modern cloud. To harness the full power of cloud, you can’t leave out some of the most important ingredients and just layer them on top later. This is what a lot of our niche competitors have done when it comes to social, mobile, big data and analytics, and other key technologies impacting the way we do business. The transformational power of these technology trends comes from having a strategy from the get-go that combines them into a winning recipe, and delivers them in a unified way. In looking at ways Oracle’s cloud is different from other clouds – not only is breadth of functionality rich across functional pillars like CRM, HCM, ERP, etc. but it embeds social, mobile, and rich intelligence capabilities where they make the most sense across business processes. This strategy enables the Oracle Cloud to uniquely deliver on all three of these dimensions to help our customers unlock the full power of these transformational technologies.

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• Pirates, Treasure Chests and Architectural Mapping

  Pirate 1: Why do pirates create treasure maps? Pirate 2: I do not know.Pirate 1: So they can find their gold. Yes, that was a bad joke, but it does illustrate a point. Pirates are known for drawing treasure maps to their most prized possession. These documents detail the decisions pirates made in order to hide and find their chests of gold. The map allows them to trace the steps they took originally to hide their treasure so that they may return. As software engineers, programmers, and architects we need to treat software implementations much like our treasure chest. Why is software like a treasure chest? It cost money, time,  and resources to develop (Usually) It can make or save money, time, and resources (Hopefully) If we operate under the assumption that software is like a treasure chest then wouldn’t make sense to document the steps, rationale, concerns, and decisions about how it was designed? Pirates are notorious for documenting where they hide their treasure.  Shouldn’t we as creators of software do the same? By documenting our design decisions and rationale behind them will help others be able to understand and maintain implemented systems. This can only be done if the design decisions are correctly mapped to its corresponding implementation. This allows for architectural decisions to be traced from the conceptual model, architectural design and finally to the implementation. Mapping gives software professional a method to trace the reason why specific areas of code were developed verses other options. Just like the pirates we need to able to trace our steps from the start of a project to its implementation,  so that we will understand why specific choices were chosen. The traceability of a software implementation that actually maps back to its originating design decisions is invaluable for ensuring that architectural drifting and erosion does not take place. The drifting and erosion is prevented by allowing others to understand the rational of why an implementation was created in a specific manor or methodology The process of mapping distinct design concerns/decisions to the location of its implemented is called traceability. In this context traceability is defined as method for connecting distinctive software artifacts. This process allows architectural design models and decisions to be directly connected with its physical implementation. The process of mapping architectural design concerns to a software implementation can be very complex. However, most design decision can be placed in  a few generalized categories. Commonly Mapped Design Decisions Design Rationale Components and Connectors Interfaces Behaviors/Properties Design rational is one of the hardest categories to map directly to an implementation. Typically this rational is mapped or document in code via comments. These comments consist of general design decisions and reasoning because they do not directly refer to a specific part of an application. They typically focus more on the higher level concerns. Components and connectors can directly be mapped to architectural concerns. Typically concerns subdivide an application in to distinct functional areas. These functional areas then can map directly back to their originating concerns.Interfaces can be mapped back to design concerns in one of two ways. Interfaces that pertain to specific function definitions can be directly mapped back to its originating concern(s). However, more complicated interfaces require additional analysis to ensure that the proper mappings are created. Depending on the complexity some Behaviors\Properties can be translated directly into a generic implementation structure that is ready for business logic. In addition, some behaviors can be translated directly in to an actual implementation depending on the complexity and architectural tools used. Mapping design concerns to an implementation is a lot of work to maintain, but is doable. In order to ensure that concerns are mapped correctly and that an implementation correctly reflects its design concerns then one of two standard approaches are usually used. All Changes Come From ArchitectureBy forcing all application changes to come through the architectural model prior to implementation then the existing mappings will be used to locate where in the implementation changes need to occur. Allow Changes From Implementation Or Architecture By allowing changes to come from the implementation and/or the architecture then the other area must be kept in sync. This methodology is more complex compared to the previous approach.  One reason to justify the added complexity for an application is due to the fact that this approach tends to detect and prevent architectural drift and erosion. Additionally, this approach is usually maintained via software because of the complexity. Reference:Taylor, R. N., Medvidovic, N., & Dashofy, E. M. (2009). Software architecture: Foundations, theory, and practice Hoboken, NJ: John Wiley & Sons  

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• Microsoft Sql Server 2008 R2 System Databases

  For a majority of software developers little time is spent understanding the inner workings of the database management systems (DBMS) they use to store data for their applications.  I personally place myself in this grouping. In my case, I have used various versions of Microsoft’s SQL Server (2000, 2005, and 2008 R2) and just recently learned how valuable they really are when I was preparing to deliver a lecture on "SQL Server 2008 R2, System Databases". Microsoft Sql Server 2008 R2 System DatabasesSo what are system databases in MS SQL Server, and why should I know them? Microsoft uses system databases to support the SQL Server DBMS, much like a developer uses config files or database tables to support an application. These system databases individually provide specific functionality that allows MS SQL Server to function. Name Database File Log File Master master.mdf mastlog.ldf Resource mssqlsystemresource.mdf mssqlsystemresource.ldf Model model.mdf modellog.ldf MSDB msdbdata.mdf msdblog.ldf Distribution distmdl.mdf distmdl.ldf TempDB tempdb.mdf templog.ldf Master DatabaseIf you have used MS SQL Server then you should recognize the Master database especially if you used the SQL Server Management Studio (SSMS) to connect to a user created database. MS SQL Server requires the Master database in order for DBMS to start due to the information that it stores. Examples of data stored in the Master database User Logins Linked Servers Configuration information Information on User Databases Resource DatabaseHonestly, until recently I never knew this database even existed until I started to research SQL Server system databases. The reason for this is due largely to the fact that the resource database is hidden to users. In fact, the database files are stored within the Binn folder instead of the standard MS SQL Server database folder path. This database contains all system objects that can be accessed by all other databases.  In short, this database contains all system views and store procedures that appear in all other user databases regarding system information. One of the many benefits to storing system views and store procedures in a single hidden database is the fact it improves upgrading a SQL Server database; not to mention that maintenance is decreased since only one code base has to be mainlined for all of the system views and procedures. Model DatabaseThe Model database as the name implies is the model for all new databases created by users. This allows for predefining default database objects for all new databases within a MS SQL Server instance. For example, if every database created by a user needs to have an “Audit” table when it is  created then defining the “Audit” table in the model will guarantees that the table will be located in every new database create after the model is altered. MSDB DatabaseThe MSDBdatabase is used by SQL Server Agent, SQL Server Database Mail, SQL Server Service Broker, along with SQL Server. The SQL Server Agent uses this database to store job configurations and SQL job schedules along with SQL Alerts, and Operators. In addition, this database also stores all SQL job parameters along with each job’s execution history.  Finally, this database is also used to store database backup and maintenance plans as well as details pertaining to SQL Log shipping if it is being used. Distribution DatabaseThe Distribution database is only used during replication and stores meta data and history information pertaining to the act of replication data. Furthermore, when transactional replication is used this database also stores information regarding each transaction. It is important to note that replication is not turned on by default in MS SQL Server and that the distribution database is hidden from SSMS. Tempdb DatabaseThe Tempdb as the name implies is used to store temporary data and data objects. Examples of this include temp tables and temp store procedures. It is important to note that when using this database all data and data objects are cleared from this database when SQL Server restarts. This database is also used by SQL Server when it is performing some internal operations. Typically, SQL Server uses this database for the purpose of large sort and index operations. Finally, this database is used to store row versions if row versioning or snapsot isolation transactions are being used by SQL Server. Additionally, I would love to hear from others about their experiences using system databases, tables, and objects in a real world environments.

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