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• ASP.NET MVC 2 Released

  - by ScottGu

  I’m happy to announce that the final release of ASP.NET MVC 2 is now available for VS 2008/Visual Web Developer 2008 Express with ASP.NET 3.5.  You can download and install it from the following locations: Download ASP.NET MVC 2 using the Microsoft Web Platform Installer Download ASP.NET MVC 2 from the Download Center The final release of VS 2010 and Visual Web Developer 2010 will have ASP.NET MVC 2 built-in – so you won’t need an additional install in order to use ASP.NET MVC 2 with them.  ASP.NET MVC 2 We shipped ASP.NET MVC 1 a little less than a year ago.  Since then, almost 1 million developers have downloaded and used the final release, and its popularity has steadily grown month over month. ASP.NET MVC 2 is the next significant update of ASP.NET MVC. It is a compatible update to ASP.NET MVC 1 – so all the knowledge, skills, code, and extensions you already have with ASP.NET MVC continue to work and apply going forward. Like the first release, we are also shipping the source code for ASP.NET MVC 2 under an OSI-compliant open-source license. ASP.NET MVC 2 can be installed side-by-side with ASP.NET MVC 1 (meaning you can have some apps built with V1 and others built with V2 on the same machine).  We have instructions on how to update your existing ASP.NET MVC 1 apps to use ASP.NET MVC 2 using VS 2008 here.  Note that VS 2010 has an automated upgrade wizard that can automatically migrate your existing ASP.NET MVC 1 applications to ASP.NET MVC 2 for you. ASP.NET MVC 2 Features ASP.NET MVC 2 adds a bunch of new capabilities and features.  I’ve started a blog series about some of the new features, and will be covering them in more depth in the weeks ahead.  Some of the new features and capabilities include: New Strongly Typed HTML Helpers Enhanced Model Validation support across both server and client Auto-Scaffold UI Helpers with Template Customization Support for splitting up large applications into “Areas” Asynchronous Controllers support that enables long running tasks in parallel Support for rendering sub-sections of a page/site using Html.RenderAction Lots of new helper functions, utilities, and API enhancements Improved Visual Studio tooling support You can learn more about these features in the “What’s New in ASP.NET MVC 2” document on the www.asp.net/mvc web-site.  We are going to be posting a lot of new tutorials and videos shortly on www.asp.net/mvc that cover all the features in ASP.NET MVC 2 release.  We will also post an updated end-to-end tutorial built entirely with ASP.NET MVC 2 (much like the NerdDinner tutorial that I wrote that covers ASP.NET MVC 1).  Summary The ASP.NET MVC team delivered regular V2 preview releases over the last year to get feedback on the feature set.  I’d like to say a big thank you to everyone who tried out the previews and sent us suggestions/feedback/bug reports.  We hope you like the final release! Scott

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• Serious about Embedded: Java Embedded @ JavaOne 2012

  - by terrencebarr

  It bears repeating: More than ever, the Java platform is the best technology for many embedded use cases. Java’s platform independence, high level of functionality, security, and developer productivity address the key pain points in building embedded solutions. Transitioning from 16 to 32 bit or even 64 bit? Need to support multiple architectures and operating systems with a single code base? Want to scale on multi-core systems? Require a proven security model? Dynamically deploy and manage software on your devices? Cut time to market by leveraging code, expertise, and tools from a large developer ecosystem? Looking for back-end services, integration, and management? The Java platform has got you covered. Java already powers around 10 billion devices worldwide, with traditional desktops and servers being only a small portion of that. And the ‘Internet of Things‘ is just really starting to explode … it is estimated that within five years, intelligent and connected embedded devices will outnumber desktops and mobile phones combined, and will generate the majority of the traffic on the Internet. Is your platform and services strategy ready for the coming disruptions and opportunities? It should come as no surprise that Oracle is keenly focused on Java for Embedded. At JavaOne 2012 San Francisco the dedicated track for Java ME, Java Card, and Embedded keeps growing, with 52 sessions, tutorials, Hands-on-Labs, and BOFs scheduled for this track alone, plus keynotes, demos, booths, and a variety of other embedded content. To further prove Oracle’s commitment, in 2012 for the first time there will be a dedicated sub-conference focused on the business aspects of embedded Java: Java Embedded @ JavaOne. This conference will run for two days in parallel to JavaOne in San Francisco, will have its own business-oriented track and content, and targets C-level executives, architects, business leaders, and decision makers. Registration and Call For Papers for Java Embedded @ JavaOne are now live. We expect a lot of interest in this new event and space is limited, so be sure to submit your paper and register soon. Hope to see you there! Cheers, – Terrence Filed under: Mobile & Embedded Tagged: ARM, Call for Papers, Embedded Java, Java Embedded, Java Embedded @ JavaOne, Java ME, Java SE Embedded, Java SE for Embedded, JavaOne San Francisco, PowerPC

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• SSIS Lookup component tuning tips

  - by jamiet

  Yesterday evening I attended a London meeting of the UK SQL Server User Group at Microsoft’s offices in London Victoria. As usual it was both a fun and informative evening and in particular there seemed to be a few questions arising about tuning the SSIS Lookup component; I rattled off some comments and figured it would be prudent to drop some of them into a dedicated blog post, hence the one you are reading right now. Scene setting A popular pattern in SSIS is to use a Lookup component to determine whether a record in the pipeline already exists in the intended destination table or not and I cover this pattern in my 2006 blog post Checking if a row exists and if it does, has it changed? (note to self: must rewrite that blog post for SSIS2008). Fundamentally the SSIS lookup component (when using FullCache option) sucks some data out of a database and holds it in memory so that it can be compared to data in the pipeline. One of the big benefits of using SSIS dataflows is that they process data one buffer at a time; that means that not all of the data from your source exists in the dataflow at the same time and is why a SSIS dataflow can process data volumes that far exceed the available memory. However, that only applies to data in the pipeline; for reasons that are hopefully obvious ALL of the data in the lookup set must exist in the memory cache for the duration of the dataflow’s execution which means that any memory used by the lookup cache will not be available to be used as a pipeline buffer. Moreover, there’s an obvious correlation between the amount of data in the lookup cache and the time it takes to charge that cache; the more data you have then the longer it will take to charge and the longer you have to wait until the dataflow actually starts to do anything. For these reasons your goal is simple: ensure that the lookup cache contains as little data as possible. General tips Here is a simple tick list you can follow in order to tune your lookups: Use a SQL statement to charge your cache, don’t just pick a table from the dropdown list made available to you. (Read why in SELECT *... or select from a dropdown in an OLE DB Source component?) Only pick the columns that you need, ignore everything else Make the database columns that your cache is populated from as narrow as possible. If a column is defined as VARCHAR(20) then SSIS will allocate 20 bytes for every value in that column – that is a big waste if the actual values are significantly less than 20 characters in length. Do you need DT_WSTR typed columns or will DT_STR suffice? DT_WSTR uses twice the amount of space to hold values that can be stored using a DT_STR so if you can use DT_STR, consider doing so. Same principle goes for the numerical datatypes DT_I2/DT_I4/DT_I8. Only populate the cache with data that you KNOW you will need. In other words, think about your WHERE clause! Thinking outside the box It is tempting to build a large monolithic dataflow that does many things, one of which is a Lookup. Often though you can make better use of your available resources by, well, mixing things up a little and here are a few ideas to get your creative juices flowing: There is no rule that says everything has to happen in a single dataflow. If you have some particularly resource intensive lookups then consider putting that lookup into a dataflow all of its own and using raw files to pass the pipeline data in and out of that dataflow. Know your data. If you think, for example, that the majority of your incoming rows will match with only a small subset of your lookup data then consider chaining multiple lookup components together; the first would use a FullCache containing that data subset and the remaining data that doesn’t find a match could be passed to a second lookup that perhaps uses a NoCache lookup thus negating the need to pull all of that least-used lookup data into memory. Do you need to process all of your incoming data all at once? If you can process different partitions of your data separately then you can partition your lookup cache as well. For example, if you are using a lookup to convert a location into a [LocationId] then why not process your data one region at a time? This will mean your lookup cache only has to contain data for the location that you are currently processing and with the ability of the Lookup in SSIS2008 and beyond to charge the cache using a dynamically built SQL statement you’ll be able to achieve it using the same dataflow and simply loop over it using a ForEach loop. Taking the previous data partitioning idea further … a dataflow can contain more than one data path so why not split your data using a conditional split component and, again, charge your lookup caches with only the data that they need for that partition. Lookups have two uses: to (1) find a matching row from the lookup set and (2) put attributes from that matching row into the pipeline. Ask yourself, do you need to do these two things at the same time? After all once you have the key column(s) from your lookup set then you can use that key to get the rest of attributes further downstream, perhaps even in another dataflow. Are you using the same lookup data set multiple times? If so, consider the file caching option in SSIS 2008 and beyond. Above all, experiment and be creative with different combinations. You may be surprised at what works. Final  thoughts If you want to know more about how the Lookup component differs in SSIS2008 from SSIS2005 then I have a dedicated blog post about that at Lookup component gets a makeover. I am on a mini-crusade at the moment to get a BULK MERGE feature into the database engine, the thinking being that if the database engine can quickly merge massive amounts of data in a similar manner to how it can insert massive amounts using BULK INSERT then that’s a lot of work that wouldn’t have to be done in the SSIS pipeline. If you think that is a good idea then go and vote for BULK MERGE on Connect. If you have any other tips to share then please stick them in the comments. Hope this helps! @Jamiet Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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• How can I get penetration depth from Minkowski Portal Refinement / Xenocollide?

  - by Raven Dreamer

  I recently got an implementation of Minkowski Portal Refinement (MPR) successfully detecting collision. Even better, my implementation returns a good estimate (local minimum) direction for the minimum penetration depth. So I took a stab at adjusting the algorithm to return the penetration depth in an arbitrary direction, and was modestly successful - my altered method works splendidly for face-edge collision resolution! What it doesn't currently do, is correctly provide the minimum penetration depth for edge-edge scenarios, such as the case on the right: What I perceive to be happening, is that my current method returns the minimum penetration depth to the nearest vertex - which works fine when the collision is actually occurring on the plane of that vertex, but not when the collision happens along an edge. Is there a way I can alter my method to return the penetration depth to the point of collision, rather than the nearest vertex? Here's the method that's supposed to return the minimum penetration distance along a specific direction: public static Vector3 CalcMinDistance(List<Vector3> shape1, List<Vector3> shape2, Vector3 dir) { //holding variables Vector3 n = Vector3.zero; Vector3 swap = Vector3.zero; // v0 = center of Minkowski sum v0 = Vector3.zero; // Avoid case where centers overlap -- any direction is fine in this case //if (v0 == Vector3.zero) return Vector3.zero; //always pass in a valid direction. // v1 = support in direction of origin n = -dir; //get the differnce of the minkowski sum Vector3 v11 = GetSupport(shape1, -n); Vector3 v12 = GetSupport(shape2, n); v1 = v12 - v11; //if the support point is not in the direction of the origin if (v1.Dot(n) <= 0) { //Debug.Log("Could find no points this direction"); return Vector3.zero; } // v2 - support perpendicular to v1,v0 n = v1.Cross(v0); if (n == Vector3.zero) { //v1 and v0 are parallel, which means //the direction leads directly to an endpoint n = v1 - v0; //shortest distance is just n //Debug.Log("2 point return"); return n; } //get the new support point Vector3 v21 = GetSupport(shape1, -n); Vector3 v22 = GetSupport(shape2, n); v2 = v22 - v21; if (v2.Dot(n) <= 0) { //can't reach the origin in this direction, ergo, no collision //Debug.Log("Could not reach edge?"); return Vector2.zero; } // Determine whether origin is on + or - side of plane (v1,v0,v2) //tests linesegments v0v1 and v0v2 n = (v1 - v0).Cross(v2 - v0); float dist = n.Dot(v0); // If the origin is on the - side of the plane, reverse the direction of the plane if (dist > 0) { //swap the winding order of v1 and v2 swap = v1; v1 = v2; v2 = swap; //swap the winding order of v11 and v12 swap = v12; v12 = v11; v11 = swap; //swap the winding order of v11 and v12 swap = v22; v22 = v21; v21 = swap; //and swap the plane normal n = -n; } /// // Phase One: Identify a portal while (true) { // Obtain the support point in a direction perpendicular to the existing plane // Note: This point is guaranteed to lie off the plane Vector3 v31 = GetSupport(shape1, -n); Vector3 v32 = GetSupport(shape2, n); v3 = v32 - v31; if (v3.Dot(n) <= 0) { //can't enclose the origin within our tetrahedron //Debug.Log("Could not reach edge after portal?"); return Vector3.zero; } // If origin is outside (v1,v0,v3), then eliminate v2 and loop if (v1.Cross(v3).Dot(v0) < 0) { //failed to enclose the origin, adjust points; v2 = v3; v21 = v31; v22 = v32; n = (v1 - v0).Cross(v3 - v0); continue; } // If origin is outside (v3,v0,v2), then eliminate v1 and loop if (v3.Cross(v2).Dot(v0) < 0) { //failed to enclose the origin, adjust points; v1 = v3; v11 = v31; v12 = v32; n = (v3 - v0).Cross(v2 - v0); continue; } bool hit = false; /// // Phase Two: Refine the portal int phase2 = 0; // We are now inside of a wedge... while (phase2 < 20) { phase2++; // Compute normal of the wedge face n = (v2 - v1).Cross(v3 - v1); n.Normalize(); // Compute distance from origin to wedge face float d = n.Dot(v1); // If the origin is inside the wedge, we have a hit if (d > 0 ) { //Debug.Log("Do plane test here"); float T = n.Dot(v2) / n.Dot(dir); Vector3 pointInPlane = (dir * T); return pointInPlane; } // Find the support point in the direction of the wedge face Vector3 v41 = GetSupport(shape1, -n); Vector3 v42 = GetSupport(shape2, n); v4 = v42 - v41; float delta = (v4 - v3).Dot(n); float separation = -(v4.Dot(n)); if (delta <= kCollideEpsilon || separation >= 0) { //Debug.Log("Non-convergance detected"); //Debug.Log("Do plane test here"); return Vector3.zero; } // Compute the tetrahedron dividing face (v4,v0,v1) float d1 = v4.Cross(v1).Dot(v0); // Compute the tetrahedron dividing face (v4,v0,v2) float d2 = v4.Cross(v2).Dot(v0); // Compute the tetrahedron dividing face (v4,v0,v3) float d3 = v4.Cross(v3).Dot(v0); if (d1 < 0) { if (d2 < 0) { // Inside d1 & inside d2 ==> eliminate v1 v1 = v4; v11 = v41; v12 = v42; } else { // Inside d1 & outside d2 ==> eliminate v3 v3 = v4; v31 = v41; v32 = v42; } } else { if (d3 < 0) { // Outside d1 & inside d3 ==> eliminate v2 v2 = v4; v21 = v41; v22 = v42; } else { // Outside d1 & outside d3 ==> eliminate v1 v1 = v4; v11 = v41; v12 = v42; } } } return Vector3.zero; } }

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• Hyperlinked, externalized source code documentation

  - by Dave Jarvis

  Why do we still embed natural language descriptions of source code (i.e., the reason why a line of code was written) within the source code, rather than as a separate document? Given the expansive real-estate afforded to modern development environments (high-resolution monitors, dual-monitors, etc.), an IDE could provide semi-lock-step panels wherein source code is visually separated from -- but intrinsically linked to -- its corresponding comments. For example, developers could write source code comments in a hyper-linked markup language (linking to additional software requirements), which would simultaneously prevent documentation from cluttering the source code. What shortcomings would inhibit such a software development mechanism? A mock-up to help clarify the question: When the cursor is at a particular line in the source code (shown with a blue background, above), the documentation that corresponds to the line at the cursor is highlighted (i.e., distinguished from the other details). As noted in the question, the documentation would stay in lock-step with the source code as the cursor jumps through the source code. A hot-key could switch between "documentation mode" and "development mode". Potential advantages include: More source code and more documentation on the screen(s) at once Ability to edit documentation independently of source code (regardless of language?) Write documentation and source code in parallel without merge conflicts Real-time hyperlinked documentation with superior text formatting Quasi-real-time machine translation into different natural languages Every line of code can be clearly linked to a task, business requirement, etc. Documentation could automatically timestamp when each line of code was written (metrics) Dynamic inclusion of architecture diagrams, images to explain relations, etc. Single-source documentation (e.g., tag code snippets for user manual inclusion). Note: The documentation window can be collapsed Workflow for viewing or comparing source files would not be affected How the implementation happens is a detail; the documentation could be: kept at the end of the source file; split into two files by convention (filename.c, filename.c.doc); or fully database-driven By hyperlinked documentation, I mean linking to external sources (such as StackOverflow or Wikipedia) and internal documents (i.e., a wiki on a subdomain that could cross-reference business requirements documentation) and other source files (similar to JavaDocs). Related thread: What's with the aversion to documentation in the industry?

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• SQL SERVER – Introduction to Adaptive ETL Tool – How adaptive is your ETL?

  - by pinaldave

  I am often reminded by the fact that BI/data warehousing infrastructure is very brittle and not very adaptive to change. There are lots of basic use cases where data needs to be frequently loaded into SQL Server or another database. What I have found is that as long as the sources and targets stay the same, SSIS or any other ETL tool for that matter does a pretty good job handling these types of scenarios. But what happens when you are faced with more challenging scenarios, where the data formats and possibly the data types of the source data are changing from customer to customer?  Let’s examine a real life situation where a health management company receives claims data from their customers in various source formats. Even though this company supplied all their customers with the same claims forms, they ended up building one-off ETL applications to process the claims for each customer. Why, you ask? Well, it turned out that the claims data from various regional hospitals they needed to process had slightly different data formats, e.g. “integer” versus “string” data field definitions.  Moreover the data itself was represented with slight nuances, e.g. “0001124” or “1124” or “0000001124” to represent a particular account number, which forced them, as I eluded above, to build new ETL processes for each customer in order to overcome the inconsistencies in the various claims forms.  As a result, they experienced a lot of redundancy in these ETL processes and recognized quickly that their system would become more difficult to maintain over time. So imagine for a moment that you could use an ETL tool that helps you abstract the data formats so that your ETL transformation process becomes more reusable. Imagine that one claims form represents a data item as a string – acc_no(varchar) – while a second claims form represents the same data item as an integer – account_no(integer). This would break your traditional ETL process as the data mappings are hard-wired.  But in a world of abstracted definitions, all you need to do is create parallel data mappings to a common data representation used within your ETL application; that is, map both external data fields to a common attribute whose name and type remain unchanged within the application. acc_no(varchar) is mapped to account_number(integer) expressor Studio first claim form schema mapping account_no(integer) is also mapped to account_number(integer) expressor Studio second claim form schema mapping All the data processing logic that follows manipulates the data as an integer value named account_number. Well, these are the kind of problems that that the expressor data integration solution automates for you.  I’ve been following them since last year and encourage you to check them out by downloading their free expressor Studio ETL software. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Business Intelligence, Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: ETL, SSIS

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• SSIS - XML Source Script

  - by simonsabin

  The XML Source in SSIS is great if you have a 1 to 1 mapping between entity and table. You can do more complex mapping but it becomes very messy and won't perform. What other options do you have? The challenge with XML processing is to not need a huge amount of memory. I remember using the early versions of Biztalk with loaded the whole document into memory to map from one document type to another. This was fine for small documents but was an absolute killer for large documents. You therefore need a streaming approach. For flexibility however you want to be able to generate your rows easily, and if you've ever used the XmlReader you will know its ugly code to write. That brings me on to LINQ. The is an implementation of LINQ over XML which is really nice. You can write nice LINQ queries instead of the XMLReader stuff. The downside is that by default LINQ to XML requires a whole XML document to work with. No streaming. Your code would look like this. We create an XDocument and then enumerate over a set of annoymous types we generate from our LINQ statement XDocument x = XDocument.Load("C:\\TEMP\\CustomerOrders-Attribute.xml");   foreach (var xdata in (from customer in x.Elements("OrderInterface").Elements("Customer")                        from order in customer.Elements("Orders").Elements("Order")                        select new { Account = customer.Attribute("AccountNumber").Value                                   , OrderDate = order.Attribute("OrderDate").Value }                        )) {     Output0Buffer.AddRow();     Output0Buffer.AccountNumber = xdata.Account;     Output0Buffer.OrderDate = Convert.ToDateTime(xdata.OrderDate); } As I said the downside to this is that you are loading the whole document into memory. I did some googling and came across some helpful videos from a nice UK DPE Mike Taulty http://www.microsoft.com/uk/msdn/screencasts/screencast/289/LINQ-to-XML-Streaming-In-Large-Documents.aspx. Which show you how you can combine LINQ and the XmlReader to get a semi streaming approach. I took what he did and implemented it in SSIS. What I found odd was that when I ran it I got different numbers between using the streamed and non streamed versions. I found the cause was a little bug in Mikes code that causes the pointer in the XmlReader to progress past the start of the element and thus foreach (var xdata in (from customer in StreamReader("C:\\TEMP\\CustomerOrders-Attribute.xml","Customer")                                from order in customer.Elements("Orders").Elements("Order")                                select new { Account = customer.Attribute("AccountNumber").Value                                           , OrderDate = order.Attribute("OrderDate").Value }                                ))         {             Output0Buffer.AddRow();             Output0Buffer.AccountNumber = xdata.Account;             Output0Buffer.OrderDate = Convert.ToDateTime(xdata.OrderDate);         } These look very similiar and they are the key element is the method we are calling, StreamReader. This method is what gives us streaming, what it does is return a enumerable list of elements, because of the way that LINQ works this results in the data being streamed in. static IEnumerable<XElement> StreamReader(String filename, string elementName) {     using (XmlReader xr = XmlReader.Create(filename))     {         xr.MoveToContent();         while (xr.Read()) //Reads the first element         {             while (xr.NodeType == XmlNodeType.Element && xr.Name == elementName)             {                 XElement node = (XElement)XElement.ReadFrom(xr);                   yield return node;             }         }         xr.Close();     } } This code is specifically designed to return a list of the elements with a specific name. The first Read reads the root element and then the inner while loop checks to see if the current element is the type we want. If not we do the xr.Read() again until we find the element type we want. We then use the neat function XElement.ReadFrom to read an element and all its sub elements into an XElement. This is what is returned and can be consumed by the LINQ statement. Essentially once one element has been read we need to check if we are still on the same element type and name (the inner loop) This was Mikes mistake, if we called .Read again we would advance the XmlReader beyond the start of the Element and so the ReadFrom method wouldn't work. So with the code above you can use what ever LINQ statement you like to flatten your XML into the rowsets you want. You could even have multiple outputs and generate your own surrogate keys.        

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• Using a "white list" for extracting terms for Text Mining

  - by [email protected]

  In Part 1 of my post on "Generating cluster names from a document clustering model" (part 1, part 2, part 3), I showed how to build a clustering model from text documents using Oracle Data Miner, which automates preparing data for text mining. In this process we specified a custom stoplist and lexer and relied on Oracle Text to identify important terms.  However, there is an alternative approach, the white list, which uses a thesaurus object with the Oracle Text CTXRULE index to allow you to specify the important terms. INTRODUCTIONA stoplist is used to exclude, i.e., black list, specific words in your documents from being indexed. For example, words like a, if, and, or, and but normally add no value when text mining. Other words can also be excluded if they do not help to differentiate documents, e.g., the word Oracle is ubiquitous in the Oracle product literature. One problem with stoplists is determining which words to specify. This usually requires inspecting the terms that are extracted, manually identifying which ones you don't want, and then re-indexing the documents to determine if you missed any. Since a corpus of documents could contain thousands of words, this could be a tedious exercise. Moreover, since every word is considered as an individual token, a term excluded in one context may be needed to help identify a term in another context. For example, in our Oracle product literature example, the words "Oracle Data Mining" taken individually are not particular helpful. The term "Oracle" may be found in nearly all documents, as with the term "Data." The term "Mining" is more unique, but could also refer to the Mining industry. If we exclude "Oracle" and "Data" by specifying them in the stoplist, we lose valuable information. But it we include them, they may introduce too much noise. Still, when you have a broad vocabulary or don't have a list of specific terms of interest, you rely on the text engine to identify important terms, often by computing the term frequency - inverse document frequency metric. (This is effectively a weight associated with each term indicating its relative importance in a document within a collection of documents. We'll revisit this later.) The results using this technique is often quite valuable. As noted above, an alternative to the subtractive nature of the stoplist is to specify a white list, or a list of terms--perhaps multi-word--that we want to extract and use for data mining. The obvious downside to this approach is the need to specify the set of terms of interest. However, this may not be as daunting a task as it seems. For example, in a given domain (Oracle product literature), there is often a recognized glossary, or a list of keywords and phrases (Oracle product names, industry names, product categories, etc.). Being able to identify multi-word terms, e.g., "Oracle Data Mining" or "Customer Relationship Management" as a single token can greatly increase the quality of the data mining results. The remainder of this post and subsequent posts will focus on how to produce a dataset that contains white list terms, suitable for mining. CREATING A WHITE LIST We'll leverage the thesaurus capability of Oracle Text. Using a thesaurus, we create a set of rules that are in effect our mapping from single and multi-word terms to the tokens used to represent those terms. For example, "Oracle Data Mining" becomes "ORACLEDATAMINING." First, we'll create and populate a mapping table called my_term_token_map. All text has been converted to upper case and values in the TERM column are intended to be mapped to the token in the TOKEN column. TERM                                TOKEN DATA MINING                         DATAMINING ORACLE DATA MINING                  ORACLEDATAMINING 11G                                 ORACLE11G JAVA                                JAVA CRM                                 CRM CUSTOMER RELATIONSHIP MANAGEMENT    CRM ... Next, we'll create a thesaurus object my_thesaurus and a rules table my_thesaurus_rules: CTX_THES.CREATE_THESAURUS('my_thesaurus', FALSE); CREATE TABLE my_thesaurus_rules (main_term     VARCHAR2(100),                                  query_string  VARCHAR2(400)); We next populate the thesaurus object and rules table using the term token map. A cursor is defined over my_term_token_map. As we iterate over  the rows, we insert a synonym relationship 'SYN' into the thesaurus. We also insert into the table my_thesaurus_rules the main term, and the corresponding query string, which specifies synonyms for the token in the thesaurus. DECLARE   cursor c2 is     select token, term     from my_term_token_map; BEGIN   for r_c2 in c2 loop     CTX_THES.CREATE_RELATION('my_thesaurus',r_c2.token,'SYN',r_c2.term);     EXECUTE IMMEDIATE 'insert into my_thesaurus_rules values                        (:1,''SYN(' || r_c2.token || ', my_thesaurus)'')'     using r_c2.token;   end loop; END; We are effectively inserting the token to return and the corresponding query that will look up synonyms in our thesaurus into the my_thesaurus_rules table, for example:     'ORACLEDATAMINING'        SYN ('ORACLEDATAMINING', my_thesaurus)At this point, we create a CTXRULE index on the my_thesaurus_rules table: create index my_thesaurus_rules_idx on        my_thesaurus_rules(query_string)        indextype is ctxsys.ctxrule; In my next post, this index will be used to extract the tokens that match each of the rules specified. We'll then compute the tf-idf weights for each of the terms and create a nested table suitable for mining.

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• ASP.NET Asynchronous Pages and when to use them

  - by rajbk

  There have been several articles posted about using  asynchronous pages in ASP.NET but none of them go into detail as to when you should use them. I finally found a great post by Thomas Marquardt that explains the process in depth. He addresses a key misconception also: So, in your ASP.NET application, when should you perform work asynchronously instead of synchronously? Well, only 1 thread per CPU can execute at a time.  Did you catch that?  A lot of people seem to miss this point...only one thread executes at a time on a CPU. When you have more than this, you pay an expensive penalty--a context switch. However, if a thread is blocked waiting on work...then it makes sense to switch to another thread, one that can execute now.  It also makes sense to switch threads if you want work to be done in parallel as opposed to in series, but up until a certain point it actually makes much more sense to execute work in series, again, because of the expensive context switch. Pop quiz: If you have a thread that is doing a lot of computational work and using the CPU heavily, and this takes a while, should you switch to another thread? No! The current thread is efficiently using the CPU, so switching will only incur the cost of a context switch. Ok, well, what if you have a thread that makes an HTTP or SOAP request to another server and takes a long time, should you switch threads? Yes! You can perform the HTTP or SOAP request asynchronously, so that once the "send" has occurred, you can unwind the current thread and not use any threads until there is an I/O completion for the "receive". Between the "send" and the "receive", the remote server is busy, so locally you don't need to be blocking on a thread, but instead make use of the asynchronous APIs provided in .NET Framework so that you can unwind and be notified upon completion. Again, it only makes sense to switch threads if the benefit from doing so out weights the cost of the switch. Read more about it in these posts: Performing Asynchronous Work, or Tasks, in ASP.NET Applications http://blogs.msdn.com/tmarq/archive/2010/04/14/performing-asynchronous-work-or-tasks-in-asp-net-applications.aspx ASP.NET Thread Usage on IIS 7.0 and 6.0 http://blogs.msdn.com/tmarq/archive/2007/07/21/asp-net-thread-usage-on-iis-7-0-and-6-0.aspx   PS: I generally do not write posts that simply link to other posts but think it is warranted in this case.

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• Best advice for setting up Ubuntu on my mother's computer

  - by idealmachine

  Intended use My mother had an old Compaq desktop computer running Windows 98, which she used for occasional Web browsing and playing cards. The name of her card game is Hoyle Card Games 3. Although I had to repair it several times over the last 10 years, it worked fine until it finally died at the end of last year. Hardware specifications A relative brought up a newer computer soon afterward: Operating system: Windows XP Asus K8N motherboard (with broken on-board sound; getting a sound card) Athlon 64? processor (don't remember the clock speed) 512 MB RAM Hope the graphics card works... Replacement sound card will be one of: Ensoniq ES1370 AudioPCI Diamond Monster Sound MX300 (Aureal chipset) Sound Blaster Audigy 2 SE Peripherals HP Scanjet 3400c scanner (USB connected) HP LaserJet multi-function printer (parallel port connected, and printing works with a PCL driver) Same serial mouse as old computer Question I had set up an SSH/VNC connection to allow for remotely working out problems. Or so I thought. A month later, the computer would not boot, rendering the SSH connection useless and an OS reinstall necessary. Unfortunately, I have neither the original Windows disc nor the product key. Unless I were to pay $200 for a full Windows 7 Home Premium license for my computer, I would not be able to re-install Windows XP on hers. I consider myself an advanced Linux user, having used Debian for years. So here are my questions. I have only one day to decide whether to use Ubuntu or buy Windows: A quick search leads me to believe all the hardware listed above is supposed to work with Linux, but am I mistaken? Would Ubuntu/Xubuntu suffice (specify which one if it matters), or would I be better off paying the $200 necessary for Windows XP? Is the card game likely to run on Wine? I believe the minimum system requirement is Windows 95. Failing Wine compatibility, will VirtualBox run fast enough on such a computer (Windows 98 as the guest OS)? Are there any free card games just as good? She plays mainly Bridge, Poker, and Solitaire. Is there any "Large Fonts" option for those with poor vision? The lack of it would be a big disadvantage. BONUS: Although I would probably replace the old mouse upon a move to Ubuntu, is it even possible to get a serial mouse working?

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• ORACLE Forms Upgrade Workshops

  - by Thomas Leopold

     09. Februar 2011 Workshop: Forms Upgrade von 10g (iAS) nach 11g (WLS) Oracle Deutschland lädt Sie zu einem Workshop zum Thema Forms Upgrade von 10g (iAS) nach 11g (WLS) ein. Der Workshop ist für Entwickler und Administratoren gedacht, die sich einen Überblick über die Änderungen verschaffen möchten, die sich aus der Migration von 10g auf 11g ergeben. Der Wokshop gibt einen Überblick über die architekturellen Unterschiede zwischen dem Internet Application Server und dem WebLogic Server. Er erläutert die für den Betrieb von Forms-Anwendungen relevanten Unterschiede und Gemeinsamkeiten beider Ansätze. Im HandsOn-Teil migrieren die Teilnehmer selbst einige (exemplarische) Forms-Anwendungen von 10g nach 11g und konfigurieren den WLS zum Betrieb der Forms-Module.   Agenda Beginn: 10:00 Uhr Architektur des WebLogicServers, Unterschiede 10g (iAS) und 11g (WLS) Forms unter WebLogicServer 11g Forms 11g - New Features Administration von Formsanwendungen unter 11g HandsOn: Migration von Forms-Beispielanwendungen Ende: 16:00 Uhr Termine 30. März 2011 - Potsdam | Registrieren 31. März 2011 - Hamburg | Registrieren Technische Voraussetzungen Zur Nutzung des Migrationsassistenten unter 11g müssen die Installationen 10g (iAS) und 11g (WLS) auf einem Server parallel betrieben werden. Dazu ist ein Rechner mit mindestens 4 GB RAM erforderlich; die entsprechenden Installationen werden als virtuelle Maschine zur Verfügung gestellt. Sofern Sie über keinen ausreichend dimensionierten Laptop verfügen, können wir Ihnen für den Workshop ein entsprechendes Gerät ausleihen. Bitte geben Sie dies bei der Anmeldung an, da wir nur über eine begrenzte Anzahl von Leihlaptops verfügen. Wenn Sie den Workshop auf Ihrem Laptop durchführen möchten, beachten Sie bitte die folgenden Systemvoraussetzungen 4 GB RAM Oracle VirtualBox (4.0.2) (incl. GuestAdditions) Anmeldung Zur Anmeldung nutzen Sie bitte die o.a. Links. Der Workshop ist für die Teilnehmer kostenlos. Bei Fragen oder Anmerkungen wenden Sie sich bitte an Christian Kühne (0511-95787-143)ORACLE Deutschland B.V. & Co. KGThurnithistrasse 2-630519 Hannover oder Wolfgang Kriebel (0331 2007 295) ORACLE Deutschland B.V. & Co. KGSchiffbauergasse 1414467 Potsdam ORACLE Deutschland B.V. & Co. KG, Hauptverwaltung: Riesstraße 25, D-80992 München Registergericht: Amtsgericht München, HRA 95603 Komplementärin ORACLE Deutschland Verwaltung B.V. Rijnzathe 6, 3454PV De Meern, Niederlande Handelsregister der Handelskammer Midden-Niederlande, Nr. 30143697 Geschäftsführer: Jürgen Kunz, Marcel van de Molen, Alexander van der Ven  

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• June 2013 Release of the Ajax Control Toolkit

  - by Stephen.Walther

  I’m happy to announce the June 2013 release of the Ajax Control Toolkit. For this release, we enhanced the AjaxFileUpload control to support uploading files directly to Windows Azure. We also improved the SlideShow control by adding support for CSS3 animations. You can get the latest release of the Ajax Control Toolkit by visiting the project page at CodePlex (http://AjaxControlToolkit.CodePlex.com). Alternatively, you can execute the following NuGet command from the Visual Studio Library Package Manager window: Uploading Files to Azure The AjaxFileUpload control enables you to efficiently upload large files and display progress while uploading. With this release, we’ve added support for uploading large files directly to Windows Azure Blob Storage (You can continue to upload to your server hard drive if you prefer). Imagine, for example, that you have created an Azure Blob Storage container named pictures. In that case, you can use the following AjaxFileUpload control to upload to the container: <toolkit:ToolkitScriptManager runat="server" /> <toolkit:AjaxFileUpload ID="AjaxFileUpload1" StoreToAzure="true" AzureContainerName="pictures" runat="server" /> Notice that the AjaxFileUpload control is declared with two properties related to Azure. The StoreToAzure property causes the AjaxFileUpload control to upload a file to Azure instead of the local computer. The AzureContainerName property points to the blob container where the file is uploaded. .int3{position:absolute;clip:rect(487px,auto,auto,444px);}SMALL cash advance VERY CHEAP To use the AjaxFileUpload control, you need to modify your web.config file so it contains some additional settings. You need to configure the AjaxFileUpload handler and you need to point your Windows Azure connection string to your Blob Storage account. <configuration> <appSettings> <!--<add key="AjaxFileUploadAzureConnectionString" value="UseDevelopmentStorage=true"/>--> <add key="AjaxFileUploadAzureConnectionString" value="DefaultEndpointsProtocol=https;AccountName=testact;AccountKey=RvqL89Iw4npvPlAAtpOIPzrinHkhkb6rtRZmD0+ojZupUWuuAVJRyyF/LIVzzkoN38I4LSr8qvvl68sZtA152A=="/> </appSettings> <system.web> <compilation debug="true" targetFramework="4.5" /> <httpRuntime targetFramework="4.5" /> <httpHandlers> <add verb="*" path="AjaxFileUploadHandler.axd" type="AjaxControlToolkit.AjaxFileUploadHandler, AjaxControlToolkit"/> </httpHandlers> </system.web> <system.webServer> <validation validateIntegratedModeConfiguration="false" /> <handlers> <add name="AjaxFileUploadHandler" verb="*" path="AjaxFileUploadHandler.axd" type="AjaxControlToolkit.AjaxFileUploadHandler, AjaxControlToolkit"/> </handlers> <security> <requestFiltering> <requestLimits maxAllowedContentLength="4294967295"/> </requestFiltering> </security> </system.webServer> </configuration> You supply the connection string for your Azure Blob Storage account with the AjaxFileUploadAzureConnectionString property. If you set the value “UseDevelopmentStorage=true” then the AjaxFileUpload will upload to the simulated Blob Storage on your local machine. After you create the necessary configuration settings, you can use the AjaxFileUpload control to upload files directly to Azure (even very large files). Here’s a screen capture of how the AjaxFileUpload control appears in Google Chrome: After the files are uploaded, you can view the uploaded files in the Windows Azure Portal. You can see that all 5 files were uploaded successfully: New AjaxFileUpload Events In response to user feedback, we added two new events to the AjaxFileUpload control (on both the server and the client): · UploadStart – Raised on the server before any files have been uploaded. · UploadCompleteAll – Raised on the server when all files have been uploaded. · OnClientUploadStart – The name of a function on the client which is called before any files have been uploaded. · OnClientUploadCompleteAll – The name of a function on the client which is called after all files have been uploaded. These new events are most useful when uploading multiple files at a time. The updated AjaxFileUpload sample page demonstrates how to use these events to show the total amount of time required to upload multiple files (see the AjaxFileUpload.aspx file in the Ajax Control Toolkit sample site). SlideShow Animated Slide Transitions With this release of the Ajax Control Toolkit, we also added support for CSS3 animations to the SlideShow control. The animation is used when transitioning from one slide to another. Here’s the complete list of animations: · FadeInFadeOut · ScaleX · ScaleY · ZoomInOut · Rotate · SlideLeft · SlideDown You specify the animation which you want to use by setting the SlideShowAnimationType property. For example, here is how you would use the Rotate animation when displaying a set of slides: <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="ShowSlideShow.aspx.cs" Inherits="TestACTJune2013.ShowSlideShow" %> <%@ Register TagPrefix="toolkit" Namespace="AjaxControlToolkit" Assembly="AjaxControlToolkit" %> <script runat="Server" type="text/C#"> [System.Web.Services.WebMethod] [System.Web.Script.Services.ScriptMethod] public static AjaxControlToolkit.Slide[] GetSlides() { return new AjaxControlToolkit.Slide[] { new AjaxControlToolkit.Slide("slides/Blue hills.jpg", "Blue Hills", "Go Blue"), new AjaxControlToolkit.Slide("slides/Sunset.jpg", "Sunset", "Setting sun"), new AjaxControlToolkit.Slide("slides/Winter.jpg", "Winter", "Wintery..."), new AjaxControlToolkit.Slide("slides/Water lilies.jpg", "Water lillies", "Lillies in the water"), new AjaxControlToolkit.Slide("slides/VerticalPicture.jpg", "Sedona", "Portrait style picture") }; } </script> <!DOCTYPE html> <html > <head runat="server"> <title></title> </head> <body> <form id="form1" runat="server"> <div> <toolkit:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server" /> <asp:Image ID="Image1" Height="300" Runat="server" /> <toolkit:SlideShowExtender ID="SlideShowExtender1" TargetControlID="Image1" SlideShowServiceMethod="GetSlides" AutoPlay="true" Loop="true" SlideShowAnimationType="Rotate" runat="server" /> </div> </form> </body> </html> In the code above, the set of slides is exposed by a page method named GetSlides(). The SlideShowAnimationType property is set to the value Rotate. The following animated GIF gives you an idea of the resulting slideshow: If you want to use either the SlideDown or SlideRight animations, then you must supply both an explicit width and height for the Image control which is the target of the SlideShow extender. For example, here is how you would declare an Image and SlideShow control to use a SlideRight animation: <toolkit:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server" /> <asp:Image ID="Image1" Height="300" Width="300" Runat="server" /> <toolkit:SlideShowExtender ID="SlideShowExtender1" TargetControlID="Image1" SlideShowServiceMethod="GetSlides" AutoPlay="true" Loop="true" SlideShowAnimationType="SlideRight" runat="server" /> Notice that the Image control includes both a Height and Width property. Here’s an approximation of this animation using an animated GIF: Summary The Superexpert team worked hard on this release. We hope you like the new improvements to both the AjaxFileUpload and the SlideShow controls. We’d love to hear your feedback in the comments. On to the next sprint!

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• The Niantic Project: Ingress by Felicia Hajra-Lee

  Despite the current fact that the augmented reality game for Android is still in beta phase, it is amazing to see that the world of literature is already taking momentum on this 'real-life' universe. After reading 'The Alignment: Ingress' by Thomas Greanias it took only a blink of the eye to go for 'The Niantic Project: Ingress' by Felicia Hajra-Lee, too. Here is the review I posted on Amazon.com: Ingress, a parallel universe to our reality, is here. There is no doubt about this anymore... The Niantic Project, originated at the CERN collider in Geneva, Switzerland, got into focus of global players. And the game is hard; fair-play is only for the fainted ones. Felicia understands to drag the audience directly into the action of the Niantic Project and its protagonists. The novella is heavily based on the investigations posted daily on the website of Ingress. She really understands how to interweave the various clues and creates an atmosphere where it sometimes feels challenging to differentiate between fiction and reality. It all starts with 'Epiphany Night' at the Niantic Labs, the high exposure of Exotic Matter (XM) and the escape of scientist Dr. Devra Bogdanovich and 'sentinel' Roland Jarvis. Of course, a new research, or should we name it technology, like the Niantic Project has to be protected and there are multiple parties on the hunt. Throughout the various chapters Felicia introduces new potential buyers from all over the globe, gives us detailed insights on the hunters and their brutal effectiveness to finish an assignment, and manages to keep the reader in high-pitched mode thanks to a couple of turn-arounds in the overall story. Personally, I have to say that I really enjoyed reading this title. Felicia's love to details is absolutely amazing, and sometimes I was really wondering whether she would be one of the assassins. But unfortunately I also have to say that I'm not a great fan of the structural organization of the (title-less) chapters. It is fascinating to follow the ventures of Devra, Farlowe and 855 but occasionally I had to go back to previous paragraphs in order to keep track of the individual plots. Overall a great title, captivating and rich in details but simply too short. Please Fecilia, gives us more to read. As an owner of an Android smartphone or tablet, you should get yourself into the world of Ingress. Check out the Play Store to install the app. Now. ;-)

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• C#/.NET Little Wonders: The ConcurrentDictionary

  - by James Michael Hare

  Once again we consider some of the lesser known classes and keywords of C#.  In this series of posts, we will discuss how the concurrent collections have been developed to help alleviate these multi-threading concerns.  Last week’s post began with a general introduction and discussed the ConcurrentStack<T> and ConcurrentQueue<T>.  Today's post discusses the ConcurrentDictionary<T> (originally I had intended to discuss ConcurrentBag this week as well, but ConcurrentDictionary had enough information to create a very full post on its own!).  Finally next week, we shall close with a discussion of the ConcurrentBag<T> and BlockingCollection<T>. For more of the "Little Wonders" posts, see the index here. Recap As you'll recall from the previous post, the original collections were object-based containers that accomplished synchronization through a Synchronized member.  While these were convenient because you didn't have to worry about writing your own synchronization logic, they were a bit too finely grained and if you needed to perform multiple operations under one lock, the automatic synchronization didn't buy much. With the advent of .NET 2.0, the original collections were succeeded by the generic collections which are fully type-safe, but eschew automatic synchronization.  This cuts both ways in that you have a lot more control as a developer over when and how fine-grained you want to synchronize, but on the other hand if you just want simple synchronization it creates more work. With .NET 4.0, we get the best of both worlds in generic collections.  A new breed of collections was born called the concurrent collections in the System.Collections.Concurrent namespace.  These amazing collections are fine-tuned to have best overall performance for situations requiring concurrent access.  They are not meant to replace the generic collections, but to simply be an alternative to creating your own locking mechanisms. Among those concurrent collections were the ConcurrentStack<T> and ConcurrentQueue<T> which provide classic LIFO and FIFO collections with a concurrent twist.  As we saw, some of the traditional methods that required calls to be made in a certain order (like checking for not IsEmpty before calling Pop()) were replaced in favor of an umbrella operation that combined both under one lock (like TryPop()). Now, let's take a look at the next in our series of concurrent collections!For some excellent information on the performance of the concurrent collections and how they perform compared to a traditional brute-force locking strategy, see this wonderful whitepaper by the Microsoft Parallel Computing Platform team here. ConcurrentDictionary – the fully thread-safe dictionary The ConcurrentDictionary<TKey,TValue> is the thread-safe counterpart to the generic Dictionary<TKey, TValue> collection.  Obviously, both are designed for quick – O(1) – lookups of data based on a key.  If you think of algorithms where you need lightning fast lookups of data and don’t care whether the data is maintained in any particular ordering or not, the unsorted dictionaries are generally the best way to go. Note: as a side note, there are sorted implementations of IDictionary, namely SortedDictionary and SortedList which are stored as an ordered tree and a ordered list respectively.  While these are not as fast as the non-sorted dictionaries – they are O(log2 n) – they are a great combination of both speed and ordering -- and still greatly outperform a linear search. Now, once again keep in mind that if all you need to do is load a collection once and then allow multi-threaded reading you do not need any locking.  Examples of this tend to be situations where you load a lookup or translation table once at program start, then keep it in memory for read-only reference.  In such cases locking is completely non-productive. However, most of the time when we need a concurrent dictionary we are interleaving both reads and updates.  This is where the ConcurrentDictionary really shines!  It achieves its thread-safety with no common lock to improve efficiency.  It actually uses a series of locks to provide concurrent updates, and has lockless reads!  This means that the ConcurrentDictionary gets even more efficient the higher the ratio of reads-to-writes you have. ConcurrentDictionary and Dictionary differences For the most part, the ConcurrentDictionary<TKey,TValue> behaves like it’s Dictionary<TKey,TValue> counterpart with a few differences.  Some notable examples of which are: Add() does not exist in the concurrent dictionary. This means you must use TryAdd(), AddOrUpdate(), or GetOrAdd().  It also means that you can’t use a collection initializer with the concurrent dictionary. TryAdd() replaced Add() to attempt atomic, safe adds. Because Add() only succeeds if the item doesn’t already exist, we need an atomic operation to check if the item exists, and if not add it while still under an atomic lock. TryUpdate() was added to attempt atomic, safe updates. If we want to update an item, we must make sure it exists first and that the original value is what we expected it to be.  If all these are true, we can update the item under one atomic step. TryRemove() was added to attempt atomic, safe removes. To safely attempt to remove a value we need to see if the key exists first, this checks for existence and removes under an atomic lock. AddOrUpdate() was added to attempt an thread-safe “upsert”. There are many times where you want to insert into a dictionary if the key doesn’t exist, or update the value if it does.  This allows you to make a thread-safe add-or-update. GetOrAdd() was added to attempt an thread-safe query/insert. Sometimes, you want to query for whether an item exists in the cache, and if it doesn’t insert a starting value for it.  This allows you to get the value if it exists and insert if not. Count, Keys, Values properties take a snapshot of the dictionary. Accessing these properties may interfere with add and update performance and should be used with caution. ToArray() returns a static snapshot of the dictionary. That is, the dictionary is locked, and then copied to an array as a O(n) operation.  GetEnumerator() is thread-safe and efficient, but allows dirty reads. Because reads require no locking, you can safely iterate over the contents of the dictionary.  The only downside is that, depending on timing, you may get dirty reads. Dirty reads during iteration The last point on GetEnumerator() bears some explanation.  Picture a scenario in which you call GetEnumerator() (or iterate using a foreach, etc.) and then, during that iteration the dictionary gets updated.  This may not sound like a big deal, but it can lead to inconsistent results if used incorrectly.  The problem is that items you already iterated over that are updated a split second after don’t show the update, but items that you iterate over that were updated a split second before do show the update.  Thus you may get a combination of items that are “stale” because you iterated before the update, and “fresh” because they were updated after GetEnumerator() but before the iteration reached them. Let’s illustrate with an example, let’s say you load up a concurrent dictionary like this: 1: // load up a dictionary. 2: var dictionary = new ConcurrentDictionary<string, int>(); 3:  4: dictionary["A"] = 1; 5: dictionary["B"] = 2; 6: dictionary["C"] = 3; 7: dictionary["D"] = 4; 8: dictionary["E"] = 5; 9: dictionary["F"] = 6; Then you have one task (using the wonderful TPL!) to iterate using dirty reads: 1: // attempt iteration in a separate thread 2: var iterationTask = new Task(() => 3: { 4: // iterates using a dirty read 5: foreach (var pair in dictionary) 6: { 7: Console.WriteLine(pair.Key + ":" + pair.Value); 8: } 9: }); And one task to attempt updates in a separate thread (probably): 1: // attempt updates in a separate thread 2: var updateTask = new Task(() => 3: { 4: // iterates, and updates the value by one 5: foreach (var pair in dictionary) 6: { 7: dictionary[pair.Key] = pair.Value + 1; 8: } 9: }); Now that we’ve done this, we can fire up both tasks and wait for them to complete: 1: // start both tasks 2: updateTask.Start(); 3: iterationTask.Start(); 4:  5: // wait for both to complete. 6: Task.WaitAll(updateTask, iterationTask); Now, if I you didn’t know about the dirty reads, you may have expected to see the iteration before the updates (such as A:1, B:2, C:3, D:4, E:5, F:6).  However, because the reads are dirty, we will quite possibly get a combination of some updated, some original.  My own run netted this result: 1: F:6 2: E:6 3: D:5 4: C:4 5: B:3 6: A:2 Note that, of course, iteration is not in order because ConcurrentDictionary, like Dictionary, is unordered.  Also note that both E and F show the value 6.  This is because the output task reached F before the update, but the updates for the rest of the items occurred before their output (probably because console output is very slow, comparatively). If we want to always guarantee that we will get a consistent snapshot to iterate over (that is, at the point we ask for it we see precisely what is in the dictionary and no subsequent updates during iteration), we should iterate over a call to ToArray() instead: 1: // attempt iteration in a separate thread 2: var iterationTask = new Task(() => 3: { 4: // iterates using a dirty read 5: foreach (var pair in dictionary.ToArray()) 6: { 7: Console.WriteLine(pair.Key + ":" + pair.Value); 8: } 9: }); The atomic Try…() methods As you can imagine TryAdd() and TryRemove() have few surprises.  Both first check the existence of the item to determine if it can be added or removed based on whether or not the key currently exists in the dictionary: 1: // try add attempts an add and returns false if it already exists 2: if (dictionary.TryAdd("G", 7)) 3: Console.WriteLine("G did not exist, now inserted with 7"); 4: else 5: Console.WriteLine("G already existed, insert failed."); TryRemove() also has the virtue of returning the value portion of the removed entry matching the given key: 1: // attempt to remove the value, if it exists it is removed and the original is returned 2: int removedValue; 3: if (dictionary.TryRemove("C", out removedValue)) 4: Console.WriteLine("Removed C and its value was " + removedValue); 5: else 6: Console.WriteLine("C did not exist, remove failed."); Now TryUpdate() is an interesting creature.  You might think from it’s name that TryUpdate() first checks for an item’s existence, and then updates if the item exists, otherwise it returns false.  Well, note quite... It turns out when you call TryUpdate() on a concurrent dictionary, you pass it not only the new value you want it to have, but also the value you expected it to have before the update.  If the item exists in the dictionary, and it has the value you expected, it will update it to the new value atomically and return true.  If the item is not in the dictionary or does not have the value you expected, it is not modified and false is returned. 1: // attempt to update the value, if it exists and if it has the expected original value 2: if (dictionary.TryUpdate("G", 42, 7)) 3: Console.WriteLine("G existed and was 7, now it's 42."); 4: else 5: Console.WriteLine("G either didn't exist, or wasn't 7."); The composite Add methods The ConcurrentDictionary also has composite add methods that can be used to perform updates and gets, with an add if the item is not existing at the time of the update or get. The first of these, AddOrUpdate(), allows you to add a new item to the dictionary if it doesn’t exist, or update the existing item if it does.  For example, let’s say you are creating a dictionary of counts of stock ticker symbols you’ve subscribed to from a market data feed: 1: public sealed class SubscriptionManager 2: { 3: private readonly ConcurrentDictionary<string, int> _subscriptions = new ConcurrentDictionary<string, int>(); 4:  5: // adds a new subscription, or increments the count of the existing one. 6: public void AddSubscription(string tickerKey) 7: { 8: // add a new subscription with count of 1, or update existing count by 1 if exists 9: var resultCount = _subscriptions.AddOrUpdate(tickerKey, 1, (symbol, count) => count + 1); 10:  11: // now check the result to see if we just incremented the count, or inserted first count 12: if (resultCount == 1) 13: { 14: // subscribe to symbol... 15: } 16: } 17: } Notice the update value factory Func delegate.  If the key does not exist in the dictionary, the add value is used (in this case 1 representing the first subscription for this symbol), but if the key already exists, it passes the key and current value to the update delegate which computes the new value to be stored in the dictionary.  The return result of this operation is the value used (in our case: 1 if added, existing value + 1 if updated). Likewise, the GetOrAdd() allows you to attempt to retrieve a value from the dictionary, and if the value does not currently exist in the dictionary it will insert a value.  This can be handy in cases where perhaps you wish to cache data, and thus you would query the cache to see if the item exists, and if it doesn’t you would put the item into the cache for the first time: 1: public sealed class PriceCache 2: { 3: private readonly ConcurrentDictionary<string, double> _cache = new ConcurrentDictionary<string, double>(); 4:  5: // adds a new subscription, or increments the count of the existing one. 6: public double QueryPrice(string tickerKey) 7: { 8: // check for the price in the cache, if it doesn't exist it will call the delegate to create value. 9: return _cache.GetOrAdd(tickerKey, symbol => GetCurrentPrice(symbol)); 10: } 11:  12: private double GetCurrentPrice(string tickerKey) 13: { 14: // do code to calculate actual true price. 15: } 16: } There are other variations of these two methods which vary whether a value is provided or a factory delegate, but otherwise they work much the same. Oddities with the composite Add methods The AddOrUpdate() and GetOrAdd() methods are totally thread-safe, on this you may rely, but they are not atomic.  It is important to note that the methods that use delegates execute those delegates outside of the lock.  This was done intentionally so that a user delegate (of which the ConcurrentDictionary has no control of course) does not take too long and lock out other threads. This is not necessarily an issue, per se, but it is something you must consider in your design.  The main thing to consider is that your delegate may get called to generate an item, but that item may not be the one returned!  Consider this scenario: A calls GetOrAdd and sees that the key does not currently exist, so it calls the delegate.  Now thread B also calls GetOrAdd and also sees that the key does not currently exist, and for whatever reason in this race condition it’s delegate completes first and it adds its new value to the dictionary.  Now A is done and goes to get the lock, and now sees that the item now exists.  In this case even though it called the delegate to create the item, it will pitch it because an item arrived between the time it attempted to create one and it attempted to add it. Let’s illustrate, assume this totally contrived example program which has a dictionary of char to int.  And in this dictionary we want to store a char and it’s ordinal (that is, A = 1, B = 2, etc).  So for our value generator, we will simply increment the previous value in a thread-safe way (perhaps using Interlocked): 1: public static class Program 2: { 3: private static int _nextNumber = 0; 4:  5: // the holder of the char to ordinal 6: private static ConcurrentDictionary<char, int> _dictionary 7: = new ConcurrentDictionary<char, int>(); 8:  9: // get the next id value 10: public static int NextId 11: { 12: get { return Interlocked.Increment(ref _nextNumber); } 13: } Then, we add a method that will perform our insert: 1: public static void Inserter() 2: { 3: for (int i = 0; i < 26; i++) 4: { 5: _dictionary.GetOrAdd((char)('A' + i), key => NextId); 6: } 7: } Finally, we run our test by starting two tasks to do this work and get the results… 1: public static void Main() 2: { 3: // 3 tasks attempting to get/insert 4: var tasks = new List<Task> 5: { 6: new Task(Inserter), 7: new Task(Inserter) 8: }; 9:  10: tasks.ForEach(t => t.Start()); 11: Task.WaitAll(tasks.ToArray()); 12:  13: foreach (var pair in _dictionary.OrderBy(p => p.Key)) 14: { 15: Console.WriteLine(pair.Key + ":" + pair.Value); 16: } 17: } If you run this with only one task, you get the expected A:1, B:2, ..., Z:26.  But running this in parallel you will get something a bit more complex.  My run netted these results: 1: A:1 2: B:3 3: C:4 4: D:5 5: E:6 6: F:7 7: G:8 8: H:9 9: I:10 10: J:11 11: K:12 12: L:13 13: M:14 14: N:15 15: O:16 16: P:17 17: Q:18 18: R:19 19: S:20 20: T:21 21: U:22 22: V:23 23: W:24 24: X:25 25: Y:26 26: Z:27 Notice that B is 3?  This is most likely because both threads attempted to call GetOrAdd() at roughly the same time and both saw that B did not exist, thus they both called the generator and one thread got back 2 and the other got back 3.  However, only one of those threads can get the lock at a time for the actual insert, and thus the one that generated the 3 won and the 3 was inserted and the 2 got discarded.  This is why on these methods your factory delegates should be careful not to have any logic that would be unsafe if the value they generate will be pitched in favor of another item generated at roughly the same time.  As such, it is probably a good idea to keep those generators as stateless as possible. Summary The ConcurrentDictionary is a very efficient and thread-safe version of the Dictionary generic collection.  It has all the benefits of type-safety that it’s generic collection counterpart does, and in addition is extremely efficient especially when there are more reads than writes concurrently. Tweet Technorati Tags: C#, .NET, Concurrent Collections, Collections, Little Wonders, Black Rabbit Coder,James Michael Hare

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• Combination of Operating Mode and Commit Strategy

  - by Kevin Yang

  If you want to populate a source into multiple targets, you may also want to ensure that every row from the source affects all targets uniformly (or separately). Let’s consider the Example Mapping below. If a row from SOURCE causes different changes in multiple targets (TARGET_1, TARGET_2 and TARGET_3), for example, it can be successfully inserted into TARGET_1 and TARGET_3, but failed to be inserted into TARGET_2, and the current Mapping Property TLO (target load order) is “TARGET_1 -> TARGET_2 -> TARGET_3”. What should Oracle Warehouse Builder do, in order to commit the appropriate data to all affected targets at the same time? If it doesn’t behave as you intended, the data could become inaccurate and possibly unusable.                                               Example Mapping In OWB, we can use Mapping Configuration Commit Strategies and Operating Modes together to achieve this kind of requirements. Below we will explore the combination of these two features and how they affect the results in the target tables Before going to the example, let’s review some of the terms we will be using (Details can be found in white paper Oracle® Warehouse Builder Data Modeling, ETL, and Data Quality Guide11g Release 2): Operating Modes: Set-Based Mode: Warehouse Builder generates a single SQL statement that processes all data and performs all operations. Row-Based Mode: Warehouse Builder generates statements that process data row by row. The select statement is in a SQL cursor. All subsequent statements are PL/SQL. Row-Based (Target Only) Mode: Warehouse Builder generates a cursor select statement and attempts to include as many operations as possible in the cursor. For each target, Warehouse Builder inserts each row into the target separately. Commit Strategies: Automatic: Warehouse Builder loads and then automatically commits data based on the mapping design. If the mapping has multiple targets, Warehouse Builder commits and rolls back each target separately and independently of other targets. Use the automatic commit when the consequences of multiple targets being loaded unequally are not great or are irrelevant. Automatic correlated: It is a specialized type of automatic commit that applies to PL/SQL mappings with multiple targets only. Warehouse Builder considers all targets collectively and commits or rolls back data uniformly across all targets. Use the correlated commit when it is important to ensure that every row in the source affects all affected targets uniformly. Manual: select manual commit control for PL/SQL mappings when you want to interject complex business logic, perform validations, or run other mappings before committing data. Combination of the commit strategy and operating mode To understand the effects of each combination of operating mode and commit strategy, I’ll illustrate using the following example Mapping. Firstly we insert 100 rows into the SOURCE table and make sure that the 99th row and 100th row have the same ID value. And then we create a unique key constraint on ID column for TARGET_2 table. So while running the example mapping, OWB tries to load all 100 rows to each of the targets. But the mapping should fail to load the 100th row to TARGET_2, because it will violate the unique key constraint of table TARGET_2. With different combinations of Commit Strategy and Operating Mode, here are the results ¦ Set-based/ Correlated Commit: Configuration of Example mapping:                                                     Result:                                                      What’s happening: A single error anywhere in the mapping triggers the rollback of all data. OWB encounters the error inserting into Target_2, it reports an error for the table and does not load the row. OWB rolls back all the rows inserted into Target_1 and does not attempt to load rows to Target_3. No rows are added to any of the target tables. ¦ Row-based/ Correlated Commit: Configuration of Example mapping:                                                   Result:                                                  What’s happening: OWB evaluates each row separately and loads it to all three targets. Loading continues in this way until OWB encounters an error loading row 100th to Target_2. OWB reports the error and does not load the row. It rolls back the row 100th previously inserted into Target_1 and does not attempt to load row 100 to Target_3. Then, if there are remaining rows, OWB will continue loading them, resuming with loading rows to Target_1. The mapping completes with 99 rows inserted into each target. ¦ Set-based/ Automatic Commit: Configuration of Example mapping: Result: What’s happening: When OWB encounters the error inserting into Target_2, it does not load any rows and reports an error for the table. It does, however, continue to insert rows into Target_3 and does not roll back the rows previously inserted into Target_1. The mapping completes with one error message for Target_2, no rows inserted into Target_2, and 100 rows inserted into Target_1 and Target_3 separately. ¦ Row-based/Automatic Commit: Configuration of Example mapping: Result: What’s happening: OWB evaluates each row separately for loading into the targets. Loading continues in this way until OWB encounters an error loading row 100 to Target_2 and reports the error. OWB does not roll back row 100th from Target_1, does insert it into Target_3. If there are remaining rows, it will continue to load them. The mapping completes with 99 rows inserted into Target_2 and 100 rows inserted into each of the other targets. Note: Automatic Correlated commit is not applicable for row-based (target only). If you design a mapping with the row-based (target only) and correlated commit combination, OWB runs the mapping but does not perform the correlated commit. In set-based mode, correlated commit may impact the size of your rollback segments. Space for rollback segments may be a concern when you merge data (insert/update or update/insert). Correlated commit operates transparently with PL/SQL bulk processing code. The correlated commit strategy is not available for mappings run in any mode that are configured for Partition Exchange Loading or that include a Queue, Match Merge, or Table Function operator. If you want to practice in your own environment, you can follow the steps: 1. Import the MDL file: commit_operating_mode.mdl 2. Fix the location for oracle module ORCL and deploy all tables under it. 3. Insert sample records into SOURCE table, using below plsql code: begin     for i in 1..99     loop         insert into source values(i, 'col_'||i);     end loop;     insert into source values(99, 'col_99'); end; 4. Configure MAPPING_1 to any combinations of operating mode and commit strategy you want to test. And make sure feature TLO of mapping is open. 5. Deploy Mapping “MAPPING_1”. 6. Run the mapping and check the result.

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• Oracle Open World starts on Sunday, Sept 30

  - by Mike Dietrich

  Oracle Open World 2012 starts on Sunday this week - and we are really looking forward to see you in one of our presentations, especially theDatabase Upgrade on SteriodsReal Speed, Real Customers, Real Secretson Monday, Oct 1, 12:15pm in Moscone South 307(just skip the lunch - the boxed food is not healthy at all): Monday, Oct 1, 12:15 PM - 1:15 PM - Moscone South - 307 Database Upgrade on Steroids:Real Speed, Real Customers, Real Secrets Mike Dietrich - Consulting Member Technical Staff, Oracle Georg Winkens - Technical Manager, Amadeus Data Processing Carol Tagliaferri - Senior Development Manager, Oracle  Looking to improve the performance of your database upgrade and learn about other ways to reduce upgrade time? Isn’t everyone? In this session, you will learn directly from Oracle’s Upgrade Development team about what you can do to speed things up. Find out about ways to reduce upgrade downtime such as using a transient logical standby database and/or Oracle GoldenGate, and get other hints and tips. Learn about new features that improve upgrade performance and reduce downtime. Hear Georg Winkens, DB Services technical manager from Amadeus, speak about his upgrade experience, and get real-life performance measurements and advice for a successful upgrade. . And don't forget: we already start on Sunday so if you'd like to learn about the SAP database upgrades at Deutsche Messe: Sunday, Sep 30, 11:15 AM - 12:00 PM - Moscone West - 2001Oracle Database Upgrade to 11g Release 2 with SAP Applications Andreas Ellerhoff - DBA, Deutsche Messe AG Mike Dietrich - Consulting Member Technical Staff, Oracle Jan Klokkers - Sr.Director SAP Development, Oracle Deutsche Messe began to use Oracle6 Database at the end of the 1980s and has been using Oracle Database technology together with SAP applications successfully since 2002. At the end of 2010, it took the first steps of an upgrade to Oracle Database 11g Release 2 (11.2), and since mid-2011, all SAP production systems there run successfully with Oracle Database 11g. This presentation explains why Deutsche Messe uses Oracle Database together with SAP applications, discusses the many reasons for the upgrade to Release 11g, and focuses on the operational top aspects from a DBA perspective. . And unfortunately the Hands-On-Lab is sold out already ... We would like to apologize but we have absolutely ZERO influence on either the number of runs or the number of available seats.  Tuesday, Oct 2, 10:15 AM - 12:45 PM - Marriott Marquis - Salon 12/13 Hands On Lab:Upgrading an Oracle Database Instance, Using Best Practices Roy Swonger - Senior Director, Software Development, Oracle Carol Tagliaferri - Senior Development Manager, Oracle Mike Dietrich - Consulting Member Technical Staff, Oracle Cindy Lim - PMTS, Oracle Carol Palmer - Principal Product Manager, Oracle This hands-on lab gives participants the opportunity to work through a database upgrade from an older release of Oracle Database to the very latest Oracle Database release available. Participants will learn how the improved automation of the upgrade process and the generation of fix-up scripts can quickly help fix database issues prior to upgrading. The lab also uses the new parallel upgrade feature to improve performance of the upgrade, resulting in less downtime. Come get inside information about database upgrades from the Database Upgrade development team. . See you soon

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• Why You Should Attend MySQL Connect, and Register Now

  - by Bertrand Matthelié

  MySQL Connect is taking place on September 29 and 30 in San Francisco. The early bird discount enabling you to save US$ 500 is only running for a few more days, until July 13. Are you still wondering if you should sign up? Here are 10 reasons why you definitely should: Learn from other companies how they tackled similar challenges to the ones you’re facing. Find out what they learned along the way, and how you can save time, money and a lot of troubles by avoiding repeating the same mistakes and applying the best practices they’ve developed. You’ll get the chance to hear from organizations including PayPal, Verizon, Twitter, Facebook, Ticketmaster, Ning, Mozilla, CERN, Yahoo! and more! Don’t miss this unique opportunity to meet the engineers developing and supporting the MySQL products in a single location. You’ll be able to ask them all your questions, which can represent a huge time and money saver. Acquire detailed knowledge about InnoDB, the MySQL Optimizer, High Availability strategies, improving performance and scalability, enhancing security and numerous other topics. You’ll hear it straight "from the horse’s mouth" as well as from other MySQL experts in the ecosystem. Get a better understanding about Oracle’s MySQL strategy and about the MySQL roadmap, so you can better plan where to use the MySQL database and MySQL Cluster for your next web, cloud-based and other applications. Get hands-on experience about improving performance with the MySQL Performance Schema, about using MySQL Utilities, MySQL Cluster and a lot more with eight different Hands-On Labs. Express your ideas, engage into discussions and help influence the MySQL roadmap during Birds-of-a-feather sessions about replication, backup, query optimizations and other topics. Meet partners and learn about third party tools that could be useful in your architecture. Immerse yourself into the MySQL universe and hang out with MySQL experts for two days. The discussions as well as the relationships you will create can be priceless and help you execute on your next projects in a much better and faster way. Register Now to save US$500 by taking advantage of the Early bird discount running until July 13. We’ll have parallel tracks so you should consider sending a few team members to make the most of the event. Are you attending or planning to attend Oracle OpenWorld or JavaOne? You can add MySQL Connect to your registration for only US$100! Finally, it’s always a lot of fun to attend a MySQL conference. The passion and the energy are contagious…and you’ll likely get plenty of new ideas. You will find all information about the program in the MySQL Connect Content Catalog. We look forward to seeing you there! You can also read interviews with Tomas Ulin and Ronald Bradford about MySQL Connect. Sponsorship and exhibit opportunities are still available for the conference. You will find more information here.

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• At most how many customized P3 attributes could be added into Agile?

  - by Jie Chen

  I have one customer/Oracle Partner Consultant asking me such question: how many customized attributes can be allowed to add to Agile's subclass Page Three? I never did research against this because Agile User Guide never says this and theoretically Agile supports unlimited amount of customized attributes, unless the browser itself cannot handle them in allocated memory. However my customers says when to add almost 1000 attributes, the browser (Web Client) will not show any Page Three attributes, including all the out-of-box attributes. Let's see why. Analysis It is horrible to add 1000 attributes manually. Let's do it by a batch SQL like below to add them to Item's subclass Page Three tab. Do not execute below SQL because it will not take effect due to your different node id. CREATE OR REPLACE PROCEDURE createP3Text(v_name IN VARCHAR2) IS v_nid NUMBER; v_pid NUMBER; BEGIN select SEQNODETABLE.nextval into v_nid from dual; Insert Into nodeTable ( id,parentID,description,objType,inherit,helpID,version,name ) values ( v_nid,2473003, v_name ,1,0,0,0, v_name); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,0,2,1,0,1,925, null); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,1,0,0,0,0,1,'0'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,1,0,0,0,0,2,'0'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,1,2,2,0,1,3,'50'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,0,2,1,0,1,5, null); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,0,2,2,0,1,6,'50'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,0,2,2,0,0,7,'0'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,0,4,1,451,1,8,'0'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,0,4,1,451,1,9,'1'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,1,2,1,0,1,10,v_name); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,1,0,0,0,0,11,'0'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,1,4,1,11743,1,14,'2'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,0,2,1,0,1,30, null); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,0,2,1,0,1,38, null); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,1,4,1,451,0,59,'1'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,1,4,1,451,0,60,'1'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,1,4,1,724,0,61, null); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,1,2,1,0,0,232,'0'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,1,4,1,451,0,233,'1'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,0,4,1,12239,1,415,'13307'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,1,2,1,0,0,605,'0'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,0,4,1,451,1,610,'0'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,1,4,1,451,0,716,'1'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,0,4,1,451,1,795,'0'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,0,4,1,2000008821,1,864,'2'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,0,4,1,451,1,923,'0'); Insert Into propertyTable ( ID,parentID,readOnly,attType,dataType,selection,visible,propertyID,value ) values ( SEQPROPERTYTABLE.nextval,v_nid,0,4,1,451,0,719,'0'); Insert Into tableInfo ( tabID,tableID,classID,att,ordering ) values ( 2473005,1501,2473002,v_nid,9999); commit; END createP3Text; / BEGIN FOR i in 1..1000 LOOP createP3Text('MyText' || i); END LOOP; END; / DROP PROCEDURE createP3Text; COMMIT; Now restart Agile Server and check the Server's log, we noticed below: ***** Node Created : 85625 ***** Property Created : 184579 +++++++++++++++++++++++++++++++++++++ + Agile PLM Server Starting Up... + +++++++++++++++++++++++++++++++++++++ However the previously log before batch SQL is ***** Node Created : 84625 ***** Property Created : 157579 +++++++++++++++++++++++++++++++++++++ + Agile PLM Server Starting Up... + +++++++++++++++++++++++++++++++++++++ Obviously we successfully imported 1000 (85625-84625) attributes. Now go to JavaClient and confirm if we have them or not. Theoretically we are able to open such item object and see all these 1000 attributes and their values, but we get below error. We have no error tips in server log. But never mind we have the Java Console for JavaClient. If to open the same item in JavaClient we get a clear error and detailed trace in Java Console. ORA-01795: maximum number of expressions in a list is 1000 java.sql.SQLException: ORA-01795: maximum number of expressions in a list is 1000 at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:125) ... ... at weblogic.jdbc.wrapper.PreparedStatement.executeQuery(PreparedStatement.java:128) at com.agile.pc.cmserver.base.AgileFlexUtil.setFlexValuesForOneRowTable(AgileFlexUtil.java:1104) at com.agile.pc.cmserver.base.BaseFlexTableDAO.loadExtraFlexAttValues(BaseFlexTableDAO.java:111) at com.agile.pc.cmserver.base.BasePageThreeDAO.loadTable(BasePageThreeDAO.java:108) If you are interested in the background of the problem, you may de-compile the class com.agile.pc.cmserver.base.AgileFlexUtil.setFlexValuesForOneRowTable and find the root cause that Agile happens to hit Oracle Database's limitation that more than 1000 values in the "IN" clause. Check here http://ora-01795.ora-code.com If you need Oracle Agile's final solution, please contact Oracle Agile Support. Performance Below two screenshot are jvm heap usage from before-SQL and after-SQL. We can see there is no big memory gap between two cases. So definitely there is no performance impact to Agile Application Server unless you have more than 1000 attributes for EACH of your dozens of  subclasses. And for client, 1000 attributes should not impact the browser's performance because in HTML we only use dt and dd for each attribute's pair: label and value. It is quite lightweight.

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• Advice Needed: Developers blocked by waiting on code to merge from another branch using GitFlow

  - by fogwolf

  Our team just made the switch from FogBugz & Kiln/Mercurial to Jira & Stash/Git. We are using the Git Flow model for branching, adding subtask branches off of feature branches (relating to Jira subtasks of Jira features). We are using Stash to assign a reviewer when we create a pull request to merge back into the parent branch (usually develop but for subtasks back into the feature branch). The problem we're finding is that even with the best planning and breakdown of feature cases, when multiple developers are working together on the same feature, say on the front-end and back-end, if they are working on interdependent code that is in separate branches one developer ends up blocking the other. We've tried pulling between each others' branches as we develop. We've also tried creating local integration branches each developer can pull from multiple branches to test the integration as they develop. Finally, and this seems to work possibly the best for us so far, though with a bit more overhead, we have tried creating an integration branch off of the feature branch right off the bat. When a subtask branch (off of the feature branch) is ready for a pull request and code review, we also manually merge those change sets into this feature integration branch. Then all interested developers are able to pull from that integration branch into other dependent subtask branches. This prevents anyone from waiting for any branch they are dependent upon to pass code review. I know this isn't necessarily a Git issue - it has to do with working on interdependent code in multiple branches, mixed with our own work process and culture. If we didn't have the strict code-review policy for develop (true integration branch) then developer 1 could merge to develop for developer 2 to pull from. Another complication is that we are also required to do some preliminary testing as part of the code review process before handing the feature off to QA.This means that even if front-end developer 1 is pulling directly from back-end developer 2's branch as they go, if back-end developer 2 finishes and his/her pull request is sitting in code review for a week, then front-end developer 2 technically can't create his pull request/code review because his/her code reviewer can't test because back-end developer 2's code hasn't been merged into develop yet. Bottom line is we're finding ourselves in a much more serial rather than parallel approach in these instance, depending on which route we go, and would like to find a process to use to avoid this. Last thing I'll mention is we realize by sharing code across branches that haven't been code reviewed and finalized yet we are in essence using the beta code of others. To a certain extent I don't think we can avoid that and are willing to accept that to a degree. Anyway, any ideas, input, etc... greatly appreciated. Thanks!

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• Thoughts on Nexus in SQL Server PDW

  - by jamiet

  I have been on a SQL Server Parallel Data Warehouse (aka PDW) training course this week and was interested to learn that you can't (yet) use SQL Server Management Studio (SSMS) against PDW, instead they ship a 3rd party tool called Nexus Chameleon. This was a bit of a disappointment at the beginning of the week (I'd prefer parity across SQL Server editions) but actually, having used Nexus for 3 days, I'm rather getting used to it. Some of it is a bit clunky (e.g. everything goes via an ODBC DSN) but once you get into using it its the epitome of "it just works". For example, over the past few years I have come to rely on intellisense in SSMS and have learnt to cope with its nuances. There is no intellisense in Nexus but you know what....I don't really miss it that much. In a sense its a breath of fresh air not having to hope that you've crossed the line into that will it work/won't it work grey area with SSMS intellisense. And I don't end up with writing @@CONNECTIONS instead of FROM anymore (anyone else suffer from this?) :) Moreover, Nexus is a standalone tool. Its not a bunch of features shoehorned into something else (Visual Studio). Another thing I like about Nexus is that you can actually do something with your resultset client-side. Take a look at the screenshots below:   You can see Nexus allows you to group a resultest by a column or set of columns. Nice touch. I know that many people have submitted Connect requests asking for the ability to do similar things in SSMS that would mean we don't have to copy resultsets into Excel (I know I have) - Nexus is a step in that direction. Its refreshing to use a tool that just gets out of the way yet still has some really useful features. How ironic that it gets shipped inside an edition of SQL Server! If I had the option of using Nexus in my day job I suspect that over time I would probably gravitate back to SSMS because as yet I haven’t really stretched Nexus’ capabilities, overall SSMS *does* have more features and up until now I've never really had any objections to it ... but its been an interesting awakening into the nuances that plague SSMS. Anyone else used Nexus? Any thoughts on it? @Jamiet

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• Does using GCC specific builtins qualify as incorporation within a project?

  - by DavidJFelix

  I understand that linking to a program licensed under the GPL requires that you release the source of your program under the GPL as well, while the LGPL does not require this. The terminology of the (L)GPL is very clear about this. #include "gpl_program.h" means you'd have to license GPL, because you're linking to GPL licensed code. And #include "lgpl_program.h" means you're free to license however you want, so that it doesn't explicitly prohibit linking to LGPL source. Now, my question about what isn't clear is: [begin question] GCC is GPL licensed, compiling with GCC, does not constitute "integration" into your program, as the GPL puts it; does using builtin functions (which are specific to GCC) constitute "incorporation" even though you haven't explicitly linked to this GPL licensed code? My intuition tells me that this isn't the intention, but legality isn't always intuitive. I'm not actually worried, but I'm curious if this could be considered the case. [end question] [begin aside] The reason for my equivocation is that GCC builtins like __builtin_clzl() or __builtin_expect() are an API technically and could be implemented in another way. For example, many builtins were replicated by LLVM and the argument could be made that it's not implementation specific to GCC. However, many builtins have no parallel and when compiled will link GPL licensed code in GCC and will not compile on other compilers. If you make the argument here that the API could be replicated by another compiler, couldn't you make that identical claim about any program you link to, so long as you don't distribute that source? I understand that I'm being a legal snake about this, but it strikes me as odd that the GPL isn't more specific. I don't see this as a reasonable ploy for proprietary software creators to bypass the GPL, as they'd have to bundle the GPL software to make it work, removing their plausible deniability. However, isn't it possible that if builtins don't constitute linking, then open source proponents who oppose the GPL could simply write a BSD/MIT/Apache/Apple licensed product that links to a GPL'd program and claim that they intend to write a non-GPL interface that is identical to the GPL one, preserving their BSD license until it's actually compiled? [end aside] Sorry for the aside, I didn't think many people would follow why I care about this if I'm not facing any legal trouble or implications. Don't worry too much about the hypotheticals there, I'm just extrapolating what either answer to my actual question could imply.

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• More Fun With Math

  - by PointsToShare

  More Fun with Math   The runaway student – three different ways of solving one problem Here is a problem I read in a Russian site: A student is running away. He is moving at 1 mph. Pursuing him are a lion, a tiger and his math teacher. The lion is 40 miles behind and moving at 6 mph. The tiger is 28 miles behind and moving at 4 mph. His math teacher is 30 miles behind and moving at 5 mph. Who will catch him first? Analysis Obviously we have a set of three problems. They are all basically the same, but the details are different. The problems are of the same class. Here is a little excursion into computer science. One of the things we strive to do is to create solutions for classes of problems rather than individual problems. In your daily routine, you call it re-usability. Not all classes of problems have such solutions. If a class has a general (re-usable) solution, it is called computable. Otherwise it is unsolvable. Within unsolvable classes, we may still solve individual (some but not all) problems, albeit with different approaches to each. Luckily the vast majority of our daily problems are computable, and the 3 problems of our runaway student belong to a computable class. So, let’s solve for the catch-up time by the math teacher, after all she is the most frightening. She might even make the poor runaway solve this very problem – perish the thought! Method 1 – numerical analysis. At 30 miles and 5 mph, it’ll take her 6 hours to come to where the student was to begin with. But by then the student has advanced by 6 miles. 6 miles require 6/5 hours, but by then the student advanced by another 6/5 of a mile as well. And so on and so forth. So what are we to do? One way is to write code and iterate it until we have solved it. But this is an infinite process so we’ll end up with an infinite loop. So what to do? We’ll use the principles of numerical analysis. Any calculator – your computer included – has a limited number of digits. A double floating point number is good for about 14 digits. Nothing can be computed at a greater accuracy than that. This means that we will not iterate ad infinidum, but rather to the point where 2 consecutive iterations yield the same result. When we do financial computations, we don’t even have to go that far. We stop at the 10th of a penny.  It behooves us here to stop at a 10th of a second (100 milliseconds) and this will how we will avoid an infinite loop. Interestingly this alludes to the Zeno paradoxes of motion – in particular “Achilles and the Tortoise”. Zeno says exactly the same. To catch the tortoise, Achilles must always first come to where the tortoise was, but the tortoise keeps moving – hence Achilles will never catch the tortoise and our math teacher (or lion, or tiger) will never catch the student, or the policeman the thief. Here is my resolution to the paradox. The distance and time in each step are smaller and smaller, so the student will be caught. The only thing that is infinite is the iterative solution. The race is a convergent geometric process so the steps are diminishing, but each step in the solution takes the same amount of effort and time so with an infinite number of steps, we’ll spend an eternity solving it.  This BTW is an original thought that I have never seen before. But I digress. Let’s simply write the code to solve the problem. To make sure that it runs everywhere, I’ll do it in JavaScript. function LongCatchUpTime(D, PV, FV) // D is Distance; PV is Pursuers Velocity; FV is Fugitive’ Velocity {     var t = 0;     var T = 0;     var d = parseFloat(D);     var pv = parseFloat (PV);     var fv = parseFloat (FV);     t = d / pv;     while (t > 0.000001) //a 10th of a second is 1/36,000 of an hour, I used 1/100,000     {         T = T + t;         d = t * fv;         t = d / pv;     }     return T;     } By and large, the higher the Pursuer’s velocity relative to the fugitive, the faster the calculation. Solving this with the 10th of a second limit yields: 7.499999232000001 Method 2 – Geometric Series. Each step in the iteration above is smaller than the next. As you saw, we stopped iterating when the last step was small enough, small enough not to really matter.  When we have a sequence of numbers in which the ratio of each number to its predecessor is fixed we call the sequence geometric. When we are looking at the sum of sequence, we call the sequence of sums series.  Now let’s look at our student and teacher. The teacher runs 5 times faster than the student, so with each iteration the distance between them shrinks to a fifth of what it was before. This is a fixed ratio so we deal with a geometric series.  We normally designate this ratio as q and when q is less than 1 (0 < q < 1) the sum of  + … +  is  – 1) / (q – 1). When q is less than 1, it is easier to use ) / (1 - q). Now, the steps are 6 hours then 6/5 hours then 6/5*5 and so on, so q = 1/5. And the whole series is multiplied by 6. Also because q is less than 1 , 1/  diminishes to 0. So the sum is just  / (1 - q). or 1/ (1 – 1/5) = 1 / (4/5) = 5/4. This times 6 yields 7.5 hours. We can now continue with some algebra and take it back to a simpler formula. This is arduous and I am not going to do it here. Instead let’s do some simpler algebra. Method 3 – Simple Algebra. If the time to capture the fugitive is T and the fugitive travels at 1 mph, then by the time the pursuer catches him he travelled additional T miles. Time is distance divided by speed, so…. (D + T)/V = T  thus D + T = VT  and D = VT – T = (V – 1)T  and T = D/(V – 1) This “strangely” coincides with the solution we just got from the geometric sequence. This is simpler ad faster. Here is the corresponding code. function ShortCatchUpTime(D, PV, FV) {     var d = parseFloat(D);     var pv = parseFloat (PV);     var fv = parseFloat (FV);     return d / (pv - fv); } The code above, for both the iterative solution and the algebraic solution are actually for a larger class of problems.  In our original problem the student’s velocity (speed) is 1 mph. In the code it may be anything as long as it is less than the pursuer’s velocity. As long as PV > FV, the pursuer will catch up. Here is the really general formula: T = D / (PV – FV) Finally, let’s run the program for each of the pursuers.  It could not be worse. I know he’d rather be eaten alive than suffering through yet another math lesson. See the code run? Select  “Catch Up Time” in www.mgsltns.com/games.htm The host is running on Unix, so the link is case sensitive. That’s All Folks

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• Music Notation Editor - Refactoring view creation logic elsewhere

  - by Cyril Silverman

  Let me preface by saying that knowing some elementary music theory and music notation may be helpful in grasping the problem at hand. I'm currently building a Music Notation and Tablature Editor (in Javascript). But I've come to a point where the core parts of the program are more or less there. All functionality I plan to add at this point will really build off the foundation that I've created. As a result, I want to refactor to really solidify my code. I'm using an API called VexFlow to render notation. Basically I pass the parts of the editor's state to VexFlow to build the graphical representation of the score. Here is a rough and stripped down UML diagram showing you the outline of my program: In essence, a Part has many Measures which has many Notes which has many NoteItems (yes, this is semantically weird, as a chord is represented as a Note with multiple NoteItems, individual pitches or fret positions). All of the relationships are bi-directional. There are a few problems with my design because my Measure class contains the majority of the entire application view logic. The class holds the data about all VexFlow objects (the graphical representation of the score). It contains the graphical Staff object and the graphical notes. (Shouldn't these be placed somewhere else in the program?) While VexFlowFactory deals with actual creation (and some processing) of most of the VexFlow objects, Measure still "directs" the creation of all the objects and what order they are supposed to be created in for both the VexFlowStaff and VexFlowNotes. I'm not looking for a specific answer as you'd need a much deeper understanding of my code. Just a general direction to go in. Here's a thought I had, create an MeasureView/NoteView/PartView classes that contains the basic VexFlow objects for each class in addition to any extraneous logic for it's creation? but where would these views be contained? Do I create a ScoreView that is a parallel graphical representation of everything? So that ScoreView.render() would cascade down PartView and call render for each PartView and casade down into each MeasureView, etc. Again, I just have no idea what direction to go in. The more I think about it, the more ways to go seem to pop into my head. I tried to be as concise and simplistic as possible while still getting my problem across. Please feel free to ask me any questions if anything is unclear. It's quite a struggle trying to dumb down a complicated problem to its core parts.

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• Good approach for hundreds of comsumers and big files

  - by ????? ???????

  I have several files (nearly 1GB each) with data. Data is a string line. I need to process each of these files with several hundreds of consumers. Each of these consumers does some processing that differs from others. Consumers do not write anywhere concurrently. They only need input string. After processing they update their local buffers. Consumers can easily be executed in parallel. Important: With one specific file each consumer has to process all lines (without skipping) in correct order (as they appear in file). The order of processing different files doesn't matter. Processing of a single line by one consumer is comparably fast. I expect less than 50 microseconds on Corei5. So now I'm looking for the good approach to this problem. This is going to be be a part of a .NET project, so please let's stick with .NET only (C# is preferable). I know about TPL and DataFlow. I guess that the most relevant would be BroadcastBlock. But i think that the problem here is that with each line I'll have to wait for all consumers to finish in order to post the new one. I guess that it would be not very efficient. I think that ideally situation would be something like this: One thread reads from file and writes to the buffer. Each consumer, when it is ready, reads the line from the buffer concurrently and processes it. The entry from the buffer shouldn't be deleted as one consumer reads it. It can be deleted only when all consumers have processed it. TPL schedules consumer threads itself. If one consumer outperforms the others, it shouldn't wait and can read more recent entries from the buffer. Am i right with this kind of approach? Whether yes or not, how can i implement the good solution? A bit was already discussed on StackOverflow: link

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• Am I experienced enough to learn and develop immediately using Ruby on Rails?

  - by acheong87

  General Question I understand that discussions revolving around questions of this form run the risk of becoming too specific to help others. So, perhaps a better, general question would be: What kind of experience, if any, translates easily to Ruby on Rails; and if none, then what's the learning curve like, in comparison to other popular languages? Background I have the opportunity to build a website using whatever technologies I wish to use. It's a fairly simple website, for listing products, taking payments, managing customer data, providing a back-end portal for employees to manage data, possibly hooking in flight information (the products are travel related), possibly integrating a blog and all the social-networking goodies. Specific Problem I have to let the client know by tonight whether I'm interested in taking up this project, before he talks to other potential developers, but I'm on the fence. I already work a full-time C++ development job, so the money doesn't do it for me. It's the opportunity to (be paid to) learn some new technologies and to have a real, running product in the end. I've heard and read great things about Ruby, and am really intrigued. I zipped through some introductory Ruby tutorials, no sweat. However I found the Rails tutorials a little overwhelming, especially not being able to try it out anywhere. And researching Rails hosts like Heroku and EngineYard makes me think that maybe I don't know what I'm getting myself into. The ship's leaving port! I wish I had more time to learn, better yet play with the language, but I have to decide soon! Should I venture or pass? Additional Details My experiences are in C/C++/Tcl/Perl/PHP/jQuery, and basic knowledge of Java/C#. I didn't study C.S. formally so I wasn't exposed to design principles, programming paradigms, etc., which is my greatest concern. Will my lack of understanding in this realm make RoR frustrating to learn? Will it be so incompatible with a C++ "way" of thinking that I'll wish I never started? Am I putting my client at risk by attempting this? If it helps, I'm quick to learn new things (self-taught so far) and care a great deal about correctness, using things for their intended purposes, and so on. I've read numerous recommendations of Agile Development with Rails and would love to read it (though perhaps, while developing in parallel, for shortness of time). Worse comes to worst, I'd give up and do the standard LAMP gig, of course, not charging the client for wasted time. But I'm hoping to avoid the project altogether if it's gonna come down to that! Thanks in advance for any tips, insights, votes of confidence, votes of discouragement (for the better), and such.

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