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  • CodePlex Daily Summary for Sunday, November 28, 2010

    CodePlex Daily Summary for Sunday, November 28, 2010Popular ReleasesMDownloader: MDownloader-0.15.25.7002: Fixed updater Fixed FileServe Fixed LetItBitNotepad.NET: Notepad.NET 0.7 Preview 1: Whats New?* Optimized Code Generation: Which means it will run significantly faster. * Preview of Syntax Highlighting: Only VB.NET highlighting is supported, C# and Ruby will come in Preview 2. * Improved Editing Updates (when the line number, etc updates) to be more graceful. * Recent Documents works! * Images can be inserted but they're extremely large. Known Bugs* The Update Process hangs: This is a bug apparently spawning since 0.5. It will be fixed in Preview 2. Until then, perform a fr...Flickr Schedulr: Schedulr v2.2.3984: This is v2.2 of Flickr Schedulr, a Windows desktop application that automatically uploads pictures and videos to Flickr based on a schedule (e.g. to post a new picture every day at a certain time). What's new in this release? Videos are now supported as well. The application can now automatically add pictures to the queue when it starts up, from specific monitored folders. Sets and Groups can now be displayed as text only (without icons) to speed up the application. Fixed issue that ta...Cropper: 1.9.4: Mostly fixes for issues with a few feature requests. Fixed Issues 2730 & 3638 & 14467 11044 11447 11448 11449 14665 Implemented Features 6123 11581PFC: PFC for PB 11.5: This is just a migration from the 11.0 code. No changes have been made yet (and they are needed) for it to work properly with 11.5.PDF Rider: PDF Rider 0.5: This release does not add any new feature for pdf manipulation, but enables automatic updates checking, so it is reccomended to install it in order to stay updated with next releases. Prerequisites * Microsoft Windows Operating Systems (XP - Vista - 7) * Microsoft .NET Framework 3.5 runtime * A PDF rendering software (i.e. Adobe Reader) that can be opened inside Internet Explorer. Installation instructionsChoose one of the following methods: 1. Download and run the "pdfRider0...XamlQuery/WPF - The Write Less, Do More, WPF Library: XamlQuery-WPF v1.2 (Runtime, Source): This is the first release of popular XamlQuery library for WPF. XamlQuery has already gained recognition among Silverlight developers.Math.NET Numerics: Beta 1: First beta of Math.NET Numerics. Only contains the managed linear algebra provider. Beta 2 will include the native linear algebra providers along with better documentation and examples.Minecraft GPS: Minecraft GPS 1.1: 1.1 Release New Features Compass! New style. Set opacity on main window to allow overlay of Minecraft.Microsoft All-In-One Code Framework: Visual Studio 2010 Code Samples 2010-11-25: Code samples for Visual Studio 2010Wii Backup Fusion: Wii Backup Fusion 0.8.5 Beta: - WBFS repair (default) options fixed - Transfer to image fixed - Settings ui widget names fixed - Some little bug fixes You need to reset the settings! Delete WiiBaFu's config file or registry entries on windows: Linux: ~/.config/WiiBaFu/wiibafu.conf Windows: HKEY_CURRENT_USER\Software\WiiBaFu\wiibafu Mac OS X: ~/Library/Preferences/com.wiibafu.wiibafu.plist Caution: This is a BETA version! Errors, crashes and data loss not impossible! Use in test environments only, not on productive syste...Minemapper: Minemapper v0.1.3: Added process count and world size calculation progress to the status bar. Added View->'Status Bar' menu item to show/hide the status bar. Status bar is automatically shown when loading a world. Added a prompt, when loading a world, to use or clear cached images.Sexy Select: sexy select v0.4: Changes in v0.4 Added method : elements. This returns all the option elements that are currently added to the select list Added method : selectOption. This method accepts two values, the element to be modified and the selected state. (true/false)Deep Zoom for WPF: First Release: This first release of the Deep Zoom control has the same source code, binaries and demos as the CodeProject article (http://www.codeproject.com/KB/WPF/DeepZoom.aspx).BlogEngine.NET: BlogEngine.NET 2.0 RC: This is a Release Candidate version for BlogEngine.NET 2.0. The most current, stable version of BlogEngine.NET is version 1.6. Find out more about the BlogEngine.NET 2.0 RC here. If you want to extend or modify BlogEngine.NET, you should download the source code. To get started, be sure to check out our installation documentation and the installation screencast. If you are upgrading from a previous version, please take a look at the Upgrading to BlogEngine.NET 2.0 instructions. As this ...NodeXL: Network Overview, Discovery and Exploration for Excel: NodeXL Excel Template, version 1.0.1.156: The NodeXL Excel template displays a network graph using edge and vertex lists stored in an Excel 2007 or Excel 2010 workbook. What's NewThis release adds a feature for aggregating the overall metrics in a folder full of NodeXL workbooks, adds geographical coordinates to the Twitter import features, and fixes a memory-related bug. See the Complete NodeXL Release History for details. Please Note: There is a new option in the setup program to install for "Just Me" or "Everyone." Most people...VFPX: FoxBarcode v.0.11: FoxBarcode v.0.11 - Released 2010.11.22 FoxBarcode is a 100% Visual FoxPro class that provides a tool for generating images with different bar code symbologies to be used in VFP forms and reports, or exported to other applications. Its use and distribution is free for all Visual FoxPro Community. Whats is new? Added a third parameter to the BarcodeImage() method Fixed some minor bugs History FoxBarcode v.0.10 - Released 2010.11.19 - 85 Downloads Project page: FoxBarcodeDotNetAge -a lightweight Mvc jQuery CMS: DotNetAge 1.1.0.5: What is new in DotNetAge 1.1.0.5 ?Document Library features and template added. Resolve issues of templates Improving publishing service performance Opml support added. What is new in DotNetAge 1.1 ? D.N.A Core updatesImprove runtime performance , more stabilize. The DNA core objects model added. Personalization features added that allows users create the personal website, manage their resources, store personal data DynamicUIFixed the PageManager could not move page node bug. ...ASP.NET MVC Project Awesome (jQuery Ajax helpers): 1.3.1 and demos: A rich set of helpers (controls) that you can use to build highly responsive and interactive Ajax-enabled Web applications. These helpers include Autocomplete, AjaxDropdown, Lookup, Confirm Dialog, Popup Form and Pager tested on mozilla, safari, chrome, opera, ie 9b/8/7/6DotSpatial: DotSpatial 11-21-2010: This release introduces the following Fixed bugs related to dispose, which caused issues when reordering layers in the legend Fixed bugs related to assigning categories where NULL values are in the fields New fast-acting resize using a bitmap "prediction" of what the final resize content will look like. ImageData.ReadBlock, ImageData.WriteBlock These allow direct file access for reading or writing a rectangular window. Bitmaps are used for holding the values. Removed the need to stor...New ProjectsAC: Just a simple AC ProjectAvailability Manager Project (CMPE290): Availability Manager Project (CMPE290)BCLExtensions: BCLExtensions is an extension method library for .NET 3.5 or higher which offers various extension methods for classes in the .NET Base Class Library (BCL)Command Browser 2.0 for Visual Studio: The Command Browser is a visual studio add-in that Lets you browse, and execute Visual Studio commands on the fly. It’s very handy for people that don’t tend to use bindings on daily basis and simply wants to learn new commands out of interest.EDM And T4: Generate a WCF Service from your edmxEmperor of the Multiverse: Szoftverarchitekturak rocks :)KINECT CALL: Kinect CallMultiSafepay for nopCommerce: This is MultiSafepay shop plugin voor nopCommerce. The current version supported is nopCommerce 1.60.MyGadgebydeleted: MyGadgebydeletedNHashcash: NHashcash is a .NET implementation of the Hashcash mechanism for paying for e-mail with burnt CPU cycles.OhYeah!: WP7 Note Demo ApplicationOMax - Online Market and Exchange for Real Estate: OMax Project - Online Real Estate Management System OMax stands for Online Market and eXchange and is a Real Estate management system focusing on both individuals (brokers, agents) and organizations (real estate companies) looking for online property management solutions.Opus - Silverlight UI Framework: The opus framework provides a simple way for creating UIs for Silverlight by leveraging your current MVVM structure. Outliner, the edge detection utility: Outliner is a vectorizer of the edges in the raster pictures. The new edge detection algorithm is used. It is developed in Visual C++ 2010 Express Edition, using WinAPI and STL.SharpDropBox Client for .NET: SharpDropBox Client is a DropBox client for (at first) WP7. It caches files/directories in ISO storage, and also uses Sterling DB to metadata info so that it can easily do hash checks against DropBox making it download only when there are changes. It can also be used offline.SicunSimpleDiary: ???????(????)Silverlight Navigation With Caliburn.Micro: Bring the power of the Cabliurn.Micro MVVM framework to Siliverlight 4 navigation applications. This sample application for CM shows how it can be used to create MVVM friendly Navigation applications which formerly required a view-first approach. SilverTrace - a tracer and logger for Silverlight applications: SilverTrace - a tracer and logger for Silverlight applications.StackDeck: StackDeck is a StackOverflow analysis tool written in WPFSVNHelper -- a small clean tool for visual studio: A small tool that used to clean your bin direcotry and temporary directory for the whole solutions. I usually use it before commit soure to a SVN Server. System.Xml.Serialization: Expressions.Compiler is a lightweight xml serialization framework. It is an addition to the standart .NET XML serialization. It is designed to support out-of-the-box features: * interface-driven Xml serialization * class-driven Xml serialization * runtime serializationVoXign: - Proposer une formation introductive à la langue des signes, en e-Learning. - autonomie de gestion de l’emploi du temps, du rythme - apprentissage d’un lexique de « première nécessité » - introduction à la culture sourde et approche des spécificités linguistiques de la LSF Weyland: A .NET metaprogramming framework.

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  • .NET Code Evolution

    - by Alois Kraus
    Originally posted on: http://geekswithblogs.net/akraus1/archive/2013/07/24/153504.aspxAt my day job I do look at a lot of code written by other people. Most of the code is quite good and some is even a masterpiece. And there is also code which makes you think WTF… oh it was written by me. Hm not so bad after all. There are many excuses reasons for bad code. Most often it is time pressure followed by not enough ambition (who cares) or insufficient training. Normally I do care about code quality quite a lot which makes me a (perceived) slow worker who does write many tests and refines the code quite a lot because of the design deficiencies. Most of the deficiencies I do find by putting my design under stress while checking for invariants. It does also help a lot to step into the code with a debugger (sometimes also Windbg). I do this much more often when my tests are red. That way I do get a much better understanding what my code really does and not what I think it should be doing. This time I do want to show you how code can evolve over the years with different .NET Framework versions. Once there was  time where .NET 1.1 was new and many C++ programmers did switch over to get rid of not initialized pointers and memory leaks. There were also nice new data structures available such as the Hashtable which is fast lookup table with O(1) time complexity. All was good and much code was written since then. At 2005 a new version of the .NET Framework did arrive which did bring many new things like generics and new data structures. The “old” fashioned way of Hashtable were coming to an end and everyone used the new Dictionary<xx,xx> type instead which was type safe and faster because the object to type conversion (aka boxing) was no longer necessary. I think 95% of all Hashtables and dictionaries use string as key. Often it is convenient to ignore casing to make it easy to look up values which the user did enter. An often followed route is to convert the string to upper case before putting it into the Hashtable. Hashtable Table = new Hashtable(); void Add(string key, string value) { Table.Add(key.ToUpper(), value); } This is valid and working code but it has problems. First we can pass to the Hashtable a custom IEqualityComparer to do the string matching case insensitive. Second we can switch over to the now also old Dictionary type to become a little faster and we can keep the the original keys (not upper cased) in the dictionary. Dictionary<string, string> DictTable = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase); void AddDict(string key, string value) { DictTable.Add(key, value); } Many people do not user the other ctors of Dictionary because they do shy away from the overhead of writing their own comparer. They do not know that .NET has for strings already predefined comparers at hand which you can directly use. Today in the many core area we do use threads all over the place. Sometimes things break in subtle ways but most of the time it is sufficient to place a lock around the offender. Threading has become so mainstream that it may sound weird that in the year 2000 some guy got a huge incentive for the idea to reduce the time to process calibration data from 12 hours to 6 hours by using two threads on a dual core machine. Threading does make it easy to become faster at the expense of correctness. Correct and scalable multithreading can be arbitrarily hard to achieve depending on the problem you are trying to solve. Lets suppose we want to process millions of items with two threads and count the processed items processed by all threads. A typical beginners code might look like this: int Counter; void IJustLearnedToUseThreads() { var t1 = new Thread(ThreadWorkMethod); t1.Start(); var t2 = new Thread(ThreadWorkMethod); t2.Start(); t1.Join(); t2.Join(); if (Counter != 2 * Increments) throw new Exception("Hmm " + Counter + " != " + 2 * Increments); } const int Increments = 10 * 1000 * 1000; void ThreadWorkMethod() { for (int i = 0; i < Increments; i++) { Counter++; } } It does throw an exception with the message e.g. “Hmm 10.222.287 != 20.000.000” and does never finish. The code does fail because the assumption that Counter++ is an atomic operation is wrong. The ++ operator is just a shortcut for Counter = Counter + 1 This does involve reading the counter from a memory location into the CPU, incrementing value on the CPU and writing the new value back to the memory location. When we do look at the generated assembly code we will see only inc dword ptr [ecx+10h] which is only one instruction. Yes it is one instruction but it is not atomic. All modern CPUs have several layers of caches (L1,L2,L3) which try to hide the fact how slow actual main memory accesses are. Since cache is just another word for redundant copy it can happen that one CPU does read a value from main memory into the cache, modifies it and write it back to the main memory. The problem is that at least the L1 cache is not shared between CPUs so it can happen that one CPU does make changes to values which did change in meantime in the main memory. From the exception you can see we did increment the value 20 million times but half of the changes were lost because we did overwrite the already changed value from the other thread. This is a very common case and people do learn to protect their  data with proper locking.   void Intermediate() { var time = Stopwatch.StartNew(); Action acc = ThreadWorkMethod_Intermediate; var ar1 = acc.BeginInvoke(null, null); var ar2 = acc.BeginInvoke(null, null); ar1.AsyncWaitHandle.WaitOne(); ar2.AsyncWaitHandle.WaitOne(); if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Intermediate did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Intermediate() { for (int i = 0; i < Increments; i++) { lock (this) { Counter++; } } } This is better and does use the .NET Threadpool to get rid of manual thread management. It does give the expected result but it can result in deadlocks because you do lock on this. This is in general a bad idea since it can lead to deadlocks when other threads use your class instance as lock object. It is therefore recommended to create a private object as lock object to ensure that nobody else can lock your lock object. When you read more about threading you will read about lock free algorithms. They are nice and can improve performance quite a lot but you need to pay close attention to the CLR memory model. It does make quite weak guarantees in general but it can still work because your CPU architecture does give you more invariants than the CLR memory model. For a simple counter there is an easy lock free alternative present with the Interlocked class in .NET. As a general rule you should not try to write lock free algos since most likely you will fail to get it right on all CPU architectures. void Experienced() { var time = Stopwatch.StartNew(); Task t1 = Task.Factory.StartNew(ThreadWorkMethod_Experienced); Task t2 = Task.Factory.StartNew(ThreadWorkMethod_Experienced); t1.Wait(); t2.Wait(); if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Experienced did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Experienced() { for (int i = 0; i < Increments; i++) { Interlocked.Increment(ref Counter); } } Since time does move forward we do not use threads explicitly anymore but the much nicer Task abstraction which was introduced with .NET 4 at 2010. It is educational to look at the generated assembly code. The Interlocked.Increment method must be called which does wondrous things right? Lets see: lock inc dword ptr [eax] The first thing to note that there is no method call at all. Why? Because the JIT compiler does know very well about CPU intrinsic functions. Atomic operations which do lock the memory bus to prevent other processors to read stale values are such things. Second: This is the same increment call prefixed with a lock instruction. The only reason for the existence of the Interlocked class is that the JIT compiler can compile it to the matching CPU intrinsic functions which can not only increment by one but can also do an add, exchange and a combined compare and exchange operation. But be warned that the correct usage of its methods can be tricky. If you try to be clever and look a the generated IL code and try to reason about its efficiency you will fail. Only the generated machine code counts. Is this the best code we can write? Perhaps. It is nice and clean. But can we make it any faster? Lets see how good we are doing currently. Level Time in s IJustLearnedToUseThreads Flawed Code Intermediate 1,5 (lock) Experienced 0,3 (Interlocked.Increment) Master 0,1 (1,0 for int[2]) That lock free thing is really a nice thing. But if you read more about CPU cache, cache coherency, false sharing you can do even better. int[] Counters = new int[12]; // Cache line size is 64 bytes on my machine with an 8 way associative cache try for yourself e.g. 64 on more modern CPUs void Master() { var time = Stopwatch.StartNew(); Task t1 = Task.Factory.StartNew(ThreadWorkMethod_Master, 0); Task t2 = Task.Factory.StartNew(ThreadWorkMethod_Master, Counters.Length - 1); t1.Wait(); t2.Wait(); Counter = Counters[0] + Counters[Counters.Length - 1]; if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Master did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Master(object number) { int index = (int) number; for (int i = 0; i < Increments; i++) { Counters[index]++; } } The key insight here is to use for each core its own value. But if you simply use simply an integer array of two items, one for each core and add the items at the end you will be much slower than the lock free version (factor 3). Each CPU core has its own cache line size which is something in the range of 16-256 bytes. When you do access a value from one location the CPU does not only fetch one value from main memory but a complete cache line (e.g. 16 bytes). This means that you do not pay for the next 15 bytes when you access them. This can lead to dramatic performance improvements and non obvious code which is faster although it does have many more memory reads than another algorithm. So what have we done here? We have started with correct code but it was lacking knowledge how to use the .NET Base Class Libraries optimally. Then we did try to get fancy and used threads for the first time and failed. Our next try was better but it still had non obvious issues (lock object exposed to the outside). Knowledge has increased further and we have found a lock free version of our counter which is a nice and clean way which is a perfectly valid solution. The last example is only here to show you how you can get most out of threading by paying close attention to your used data structures and CPU cache coherency. Although we are working in a virtual execution environment in a high level language with automatic memory management it does pay off to know the details down to the assembly level. Only if you continue to learn and to dig deeper you can come up with solutions no one else was even considering. I have studied particle physics which does help at the digging deeper part. Have you ever tried to solve Quantum Chromodynamics equations? Compared to that the rest must be easy ;-). Although I am no longer working in the Science field I take pride in discovering non obvious things. This can be a very hard to find bug or a new way to restructure data to make something 10 times faster. Now I need to get some sleep ….

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  • How to Load Oracle Tables From Hadoop Tutorial (Part 5 - Leveraging Parallelism in OSCH)

    - by Bob Hanckel
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Using OSCH: Beyond Hello World In the previous post we discussed a “Hello World” example for OSCH focusing on the mechanics of getting a toy end-to-end example working. In this post we are going to talk about how to make it work for big data loads. We will explain how to optimize an OSCH external table for load, paying particular attention to Oracle’s DOP (degree of parallelism), the number of external table location files we use, and the number of HDFS files that make up the payload. We will provide some rules that serve as best practices when using OSCH. The assumption is that you have read the previous post and have some end to end OSCH external tables working and now you want to ramp up the size of the loads. Using OSCH External Tables for Access and Loading OSCH external tables are no different from any other Oracle external tables.  They can be used to access HDFS content using Oracle SQL: SELECT * FROM my_hdfs_external_table; or use the same SQL access to load a table in Oracle. INSERT INTO my_oracle_table SELECT * FROM my_hdfs_external_table; To speed up the load time, you will want to control the degree of parallelism (i.e. DOP) and add two SQL hints. ALTER SESSION FORCE PARALLEL DML PARALLEL  8; ALTER SESSION FORCE PARALLEL QUERY PARALLEL 8; INSERT /*+ append pq_distribute(my_oracle_table, none) */ INTO my_oracle_table SELECT * FROM my_hdfs_external_table; There are various ways of either hinting at what level of DOP you want to use.  The ALTER SESSION statements above force the issue assuming you (the user of the session) are allowed to assert the DOP (more on that in the next section).  Alternatively you could embed additional parallel hints directly into the INSERT and SELECT clause respectively. /*+ parallel(my_oracle_table,8) *//*+ parallel(my_hdfs_external_table,8) */ Note that the "append" hint lets you load a target table by reserving space above a given "high watermark" in storage and uses Direct Path load.  In other doesn't try to fill blocks that are already allocated and partially filled. It uses unallocated blocks.  It is an optimized way of loading a table without incurring the typical resource overhead associated with run-of-the-mill inserts.  The "pq_distribute" hint in this context unifies the INSERT and SELECT operators to make data flow during a load more efficient. Finally your target Oracle table should be defined with "NOLOGGING" and "PARALLEL" attributes.   The combination of the "NOLOGGING" and use of the "append" hint disables REDO logging, and its overhead.  The "PARALLEL" clause tells Oracle to try to use parallel execution when operating on the target table. Determine Your DOP It might feel natural to build your datasets in Hadoop, then afterwards figure out how to tune the OSCH external table definition, but you should start backwards. You should focus on Oracle database, specifically the DOP you want to use when loading (or accessing) HDFS content using external tables. The DOP in Oracle controls how many PQ slaves are launched in parallel when executing an external table. Typically the DOP is something you want to Oracle to control transparently, but for loading content from Hadoop with OSCH, it's something that you will want to control. Oracle computes the maximum DOP that can be used by an Oracle user. The maximum value that can be assigned is an integer value typically equal to the number of CPUs on your Oracle instances, times the number of cores per CPU, times the number of Oracle instances. For example, suppose you have a RAC environment with 2 Oracle instances. And suppose that each system has 2 CPUs with 32 cores. The maximum DOP would be 128 (i.e. 2*2*32). In point of fact if you are running on a production system, the maximum DOP you are allowed to use will be restricted by the Oracle DBA. This is because using a system maximum DOP can subsume all system resources on Oracle and starve anything else that is executing. Obviously on a production system where resources need to be shared 24x7, this can’t be allowed to happen. The use cases for being able to run OSCH with a maximum DOP are when you have exclusive access to all the resources on an Oracle system. This can be in situations when your are first seeding tables in a new Oracle database, or there is a time where normal activity in the production database can be safely taken off-line for a few hours to free up resources for a big incremental load. Using OSCH on high end machines (specifically Oracle Exadata and Oracle BDA cabled with Infiniband), this mode of operation can load up to 15TB per hour. The bottom line is that you should first figure out what DOP you will be allowed to run with by talking to the DBAs who manage the production system. You then use that number to derive the number of location files, and (optionally) the number of HDFS data files that you want to generate, assuming that is flexible. Rule 1: Find out the maximum DOP you will be allowed to use with OSCH on the target Oracle system Determining the Number of Location Files Let’s assume that the DBA told you that your maximum DOP was 8. You want the number of location files in your external table to be big enough to utilize all 8 PQ slaves, and you want them to represent equally balanced workloads. Remember location files in OSCH are metadata lists of HDFS files and are created using OSCH’s External Table tool. They also represent the workload size given to an individual Oracle PQ slave (i.e. a PQ slave is given one location file to process at a time, and only it will process the contents of the location file.) Rule 2: The size of the workload of a single location file (and the PQ slave that processes it) is the sum of the content size of the HDFS files it lists For example, if a location file lists 5 HDFS files which are each 100GB in size, the workload size for that location file is 500GB. The number of location files that you generate is something you control by providing a number as input to OSCH’s External Table tool. Rule 3: The number of location files chosen should be a small multiple of the DOP Each location file represents one workload for one PQ slave. So the goal is to keep all slaves busy and try to give them equivalent workloads. Obviously if you run with a DOP of 8 but have 5 location files, only five PQ slaves will have something to do and the other three will have nothing to do and will quietly exit. If you run with 9 location files, then the PQ slaves will pick up the first 8 location files, and assuming they have equal work loads, will finish up about the same time. But the first PQ slave to finish its job will then be rescheduled to process the ninth location file, potentially doubling the end to end processing time. So for this DOP using 8, 16, or 32 location files would be a good idea. Determining the Number of HDFS Files Let’s start with the next rule and then explain it: Rule 4: The number of HDFS files should try to be a multiple of the number of location files and try to be relatively the same size In our running example, the DOP is 8. This means that the number of location files should be a small multiple of 8. Remember that each location file represents a list of unique HDFS files to load, and that the sum of the files listed in each location file is a workload for one Oracle PQ slave. The OSCH External Table tool will look in an HDFS directory for a set of HDFS files to load.  It will generate N number of location files (where N is the value you gave to the tool). It will then try to divvy up the HDFS files and do its best to make sure the workload across location files is as balanced as possible. (The tool uses a greedy algorithm that grabs the biggest HDFS file and delegates it to a particular location file. It then looks for the next biggest file and puts in some other location file, and so on). The tools ability to balance is reduced if HDFS file sizes are grossly out of balance or are too few. For example suppose my DOP is 8 and the number of location files is 8. Suppose I have only 8 HDFS files, where one file is 900GB and the others are 100GB. When the tool tries to balance the load it will be forced to put the singleton 900GB into one location file, and put each of the 100GB files in the 7 remaining location files. The load balance skew is 9 to 1. One PQ slave will be working overtime, while the slacker PQ slaves are off enjoying happy hour. If however the total payload (1600 GB) were broken up into smaller HDFS files, the OSCH External Table tool would have an easier time generating a list where each workload for each location file is relatively the same.  Applying Rule 4 above to our DOP of 8, we could divide the workload into160 files that were approximately 10 GB in size.  For this scenario the OSCH External Table tool would populate each location file with 20 HDFS file references, and all location files would have similar workloads (approximately 200GB per location file.) As a rule, when the OSCH External Table tool has to deal with more and smaller files it will be able to create more balanced loads. How small should HDFS files get? Not so small that the HDFS open and close file overhead starts having a substantial impact. For our performance test system (Exadata/BDA with Infiniband), I compared three OSCH loads of 1 TiB. One load had 128 HDFS files living in 64 location files where each HDFS file was about 8GB. I then did the same load with 12800 files where each HDFS file was about 80MB size. The end to end load time was virtually the same. However when I got ridiculously small (i.e. 128000 files at about 8MB per file), it started to make an impact and slow down the load time. What happens if you break rules 3 or 4 above? Nothing draconian, everything will still function. You just won’t be taking full advantage of the generous DOP that was allocated to you by your friendly DBA. The key point of the rules articulated above is this: if you know that HDFS content is ultimately going to be loaded into Oracle using OSCH, it makes sense to chop them up into the right number of files roughly the same size, derived from the DOP that you expect to use for loading. Next Steps So far we have talked about OLH and OSCH as alternative models for loading. That’s not quite the whole story. They can be used together in a way that provides for more efficient OSCH loads and allows one to be more flexible about scheduling on a Hadoop cluster and an Oracle Database to perform load operations. The next lesson will talk about Oracle Data Pump files generated by OLH, and loaded using OSCH. It will also outline the pros and cons of using various load methods.  This will be followed up with a final tutorial lesson focusing on how to optimize OLH and OSCH for use on Oracle's engineered systems: specifically Exadata and the BDA. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;}

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  • ?Oracle Database 12c????Information Lifecycle Management ILM?Storage Enhancements

    - by Liu Maclean(???)
    Oracle Database 12c????Information Lifecycle Management ILM ?????????Storage Enhancements ???????? Lifecycle Management ILM ????????? Automatic Data Placement ??????, ??ADP? ?????? 12c???????Datafile??? Online Move Datafile, ????????????????datafile???????,??????????????? ????(12.1.0.1)Automatic Data Optimization?heat map????????: ????????? (CDB)?????Automatic Data Optimization?heat map Row-level policies for ADO are not supported for Temporal Validity. Partition-level ADO and compression are supported if partitioned on the end-time columns. Row-level policies for ADO are not supported for in-database archiving. Partition-level ADO and compression are supported if partitioned on the ORA_ARCHIVE_STATE column. Custom policies (user-defined functions) for ADO are not supported if the policies default at the tablespace level. ADO does not perform checks for storage space in a target tablespace when using storage tiering. ADO is not supported on tables with object types or materialized views. ADO concurrency (the number of simultaneous policy jobs for ADO) depends on the concurrency of the Oracle scheduler. If a policy job for ADO fails more than two times, then the job is marked disabled and the job must be manually enabled later. Policies for ADO are only run in the Oracle Scheduler maintenance windows. Outside of the maintenance windows all policies are stopped. The only exceptions are those jobs for rebuilding indexes in ADO offline mode. ADO has restrictions related to moving tables and table partitions. ??????row,segment???????????ADO??,?????create table?alter table?????? ????ADO??,??????????????,???????????????? storage tier , ?????????storage tier?????????, ??????????????ADO??????????? segment?row??group? ?CREATE TABLE?ALERT TABLE???ILM???,??????????????????ADO policy? ??ILM policy???????????????? ??????? ????ADO policy, ?????alter table  ???????,?????????????? CREATE TABLE sales_ado (PROD_ID NUMBER NOT NULL, CUST_ID NUMBER NOT NULL, TIME_ID DATE NOT NULL, CHANNEL_ID NUMBER NOT NULL, PROMO_ID NUMBER NOT NULL, QUANTITY_SOLD NUMBER(10,2) NOT NULL, AMOUNT_SOLD NUMBER(10,2) NOT NULL ) ILM ADD POLICY COMPRESS FOR ARCHIVE HIGH SEGMENT AFTER 6 MONTHS OF NO ACCESS; SQL> SELECT SUBSTR(policy_name,1,24) AS POLICY_NAME, policy_type, enabled 2 FROM USER_ILMPOLICIES; POLICY_NAME POLICY_TYPE ENABLED -------------------- -------------------------- -------------- P41 DATA MOVEMENT YES ALTER TABLE sales MODIFY PARTITION sales_1995 ILM ADD POLICY COMPRESS FOR ARCHIVE HIGH SEGMENT AFTER 6 MONTHS OF NO ACCESS; SELECT SUBSTR(policy_name,1,24) AS POLICY_NAME, policy_type, enabled FROM USER_ILMPOLICIES; POLICY_NAME POLICY_TYPE ENABLE ------------------------ ------------- ------ P1 DATA MOVEMENT YES P2 DATA MOVEMENT YES /* You can disable an ADO policy with the following */ ALTER TABLE sales_ado ILM DISABLE POLICY P1; /* You can delete an ADO policy with the following */ ALTER TABLE sales_ado ILM DELETE POLICY P1; /* You can disable all ADO policies with the following */ ALTER TABLE sales_ado ILM DISABLE_ALL; /* You can delete all ADO policies with the following */ ALTER TABLE sales_ado ILM DELETE_ALL; /* You can disable an ADO policy in a partition with the following */ ALTER TABLE sales MODIFY PARTITION sales_1995 ILM DISABLE POLICY P2; /* You can delete an ADO policy in a partition with the following */ ALTER TABLE sales MODIFY PARTITION sales_1995 ILM DELETE POLICY P2; ILM ???????: ?????ILM ADP????,???????: ?????? ???? activity tracking, ????2????????,???????????????????: SEGMENT-LEVEL???????????????????? ROW-LEVEL????????,??????? ????????: 1??????? SEGMENT-LEVEL activity tracking ALTER TABLE interval_sales ILM  ENABLE ACTIVITY TRACKING SEGMENT ACCESS ???????INTERVAL_SALES??segment level  activity tracking,?????????????????? 2? ??????????? ALTER TABLE emp ILM ENABLE ACTIVITY TRACKING (CREATE TIME , WRITE TIME); 3????????? ALTER TABLE emp ILM ENABLE ACTIVITY TRACKING  (READ TIME); ?12.1.0.1.0?????? ??HEAT_MAP??????????, ?????system??session?????heap_map????????????? ?????????HEAT MAP??,? ALTER SYSTEM SET HEAT_MAP = ON; ?HEAT MAP??????,??????????????????????????  ??SYSTEM?SYSAUX????????????? ???????HEAT MAP??: ALTER SYSTEM SET HEAT_MAP = OFF; ????? HEAT_MAP????, ?HEAT_MAP??? ?????????????????????? ?HEAT_MAP?????????Automatic Data Optimization (ADO)??? ??ADO??,Heat Map ?????????? ????V$HEAT_MAP_SEGMENT ??????? HEAT MAP?? SQL> select * from V$heat_map_segment; no rows selected SQL> alter session set heat_map=on; Session altered. SQL> select * from scott.emp; EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO ---------- ---------- --------- ---------- --------- ---------- ---------- ---------- 7369 SMITH CLERK 7902 17-DEC-80 800 20 7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30 7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30 7566 JONES MANAGER 7839 02-APR-81 2975 20 7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30 7698 BLAKE MANAGER 7839 01-MAY-81 2850 30 7782 CLARK MANAGER 7839 09-JUN-81 2450 10 7788 SCOTT ANALYST 7566 19-APR-87 3000 20 7839 KING PRESIDENT 17-NOV-81 5000 10 7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30 7876 ADAMS CLERK 7788 23-MAY-87 1100 20 7900 JAMES CLERK 7698 03-DEC-81 950 30 7902 FORD ANALYST 7566 03-DEC-81 3000 20 7934 MILLER CLERK 7782 23-JAN-82 1300 10 14 rows selected. SQL> select * from v$heat_map_segment; OBJECT_NAME SUBOBJECT_NAME OBJ# DATAOBJ# TRACK_TIM SEG SEG FUL LOO CON_ID -------------------- -------------------- ---------- ---------- --------- --- --- --- --- ---------- EMP 92997 92997 23-JUL-13 NO NO YES NO 0 ??v$heat_map_segment???,?v$heat_map_segment??????????????X$HEATMAPSEGMENT V$HEAT_MAP_SEGMENT displays real-time segment access information. Column Datatype Description OBJECT_NAME VARCHAR2(128) Name of the object SUBOBJECT_NAME VARCHAR2(128) Name of the subobject OBJ# NUMBER Object number DATAOBJ# NUMBER Data object number TRACK_TIME DATE Timestamp of current activity tracking SEGMENT_WRITE VARCHAR2(3) Indicates whether the segment has write access: (YES or NO) SEGMENT_READ VARCHAR2(3) Indicates whether the segment has read access: (YES or NO) FULL_SCAN VARCHAR2(3) Indicates whether the segment has full table scan: (YES or NO) LOOKUP_SCAN VARCHAR2(3) Indicates whether the segment has lookup scan: (YES or NO) CON_ID NUMBER The ID of the container to which the data pertains. Possible values include:   0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs. 1: This value is used for rows containing data that pertain to only the root n: Where n is the applicable container ID for the rows containing data The Heat Map feature is not supported in CDBs in Oracle Database 12c, so the value in this column can be ignored. ??HEAP MAP??????????????????,????DBA_HEAT_MAP_SEGMENT???????? ???????HEAT_MAP_STAT$?????? ??Automatic Data Optimization??????: ????1: SQL> alter system set heat_map=on; ?????? ????????????? scott?? http://www.askmaclean.com/archives/scott-schema-script.html SQL> grant all on dbms_lock to scott; ????? SQL> grant dba to scott; ????? @ilm_setup_basic C:\APP\XIANGBLI\ORADATA\MACLEAN\ilm.dbf @tktgilm_demo_env_setup SQL> connect scott/tiger ; ???? SQL> select count(*) from scott.employee; COUNT(*) ---------- 3072 ??? 1 ?? SQL> set serveroutput on SQL> exec print_compression_stats('SCOTT','EMPLOYEE'); Compression Stats ------------------ Uncmpressed : 3072 Adv/basic compressed : 0 Others : 0 PL/SQL ???????? ???????3072?????? ????????? ????policy ???????????? alter table employee ilm add policy row store compress advanced row after 3 days of no modification / SQL> set serveroutput on SQL> execute list_ilm_policies; -------------------------------------------------- Policies defined for SCOTT -------------------------------------------------- Object Name------ : EMPLOYEE Subobject Name--- : Object Type------ : TABLE Inherited from--- : POLICY NOT INHERITED Policy Name------ : P1 Action Type------ : COMPRESSION Scope------------ : ROW Compression level : ADVANCED Tier Tablespace-- : Condition type--- : LAST MODIFICATION TIME Condition days--- : 3 Enabled---------- : YES -------------------------------------------------- PL/SQL ???????? SQL> select sysdate from dual; SYSDATE -------------- 29-7? -13 SQL> execute set_back_chktime(get_policy_name('EMPLOYEE',null,'COMPRESSION','ROW','ADVANCED',3,null,null),'EMPLOYEE',null,6); Object check time reset ... -------------------------------------- Object Name : EMPLOYEE Object Number : 93123 D.Object Numbr : 93123 Policy Number : 1 Object chktime : 23-7? -13 08.13.42.000000 ?? Distnt chktime : 0 -------------------------------------- PL/SQL ???????? ?policy?chktime???6??, ????set_back_chktime???????????????“????”?,?????????,???????? ?????? alter system flush buffer_cache; alter system flush buffer_cache; alter system flush shared_pool; alter system flush shared_pool; SQL> execute set_window('MONDAY_WINDOW','OPEN'); Set Maint. Window OPEN ----------------------------- Window Name : MONDAY_WINDOW Enabled? : TRUE Active? : TRUE ----------------------------- PL/SQL ???????? SQL> exec dbms_lock.sleep(60) ; PL/SQL ???????? SQL> exec print_compression_stats('SCOTT', 'EMPLOYEE'); Compression Stats ------------------ Uncmpressed : 338 Adv/basic compressed : 2734 Others : 0 PL/SQL ???????? ??????????????? Adv/basic compressed : 2734 ??????? SQL> col object_name for a20 SQL> select object_id,object_name from dba_objects where object_name='EMPLOYEE'; OBJECT_ID OBJECT_NAME ---------- -------------------- 93123 EMPLOYEE SQL> execute list_ilm_policy_executions ; -------------------------------------------------- Policies execution details for SCOTT -------------------------------------------------- Policy Name------ : P22 Job Name--------- : ILMJOB48 Start time------- : 29-7? -13 08.37.45.061000 ?? End time--------- : 29-7? -13 08.37.48.629000 ?? ----------------- Object Name------ : EMPLOYEE Sub_obj Name----- : Obj Type--------- : TABLE ----------------- Exec-state------- : SELECTED FOR EXECUTION Job state-------- : COMPLETED SUCCESSFULLY Exec comments---- : Results comments- : --- -------------------------------------------------- PL/SQL ???????? ILMJOB48?????policy?JOB,?12.1.0.1??J00x???? ?MMON_SLAVE???M00x???15????????? select sample_time,program,module,action from v$active_session_history where action ='KDILM background EXEcution' order by sample_time; 29-7? -13 08.16.38.369000000 ?? ORACLE.EXE (M000) MMON_SLAVE KDILM background EXEcution 29-7? -13 08.17.38.388000000 ?? ORACLE.EXE (M000) MMON_SLAVE KDILM background EXEcution 29-7? -13 08.17.39.390000000 ?? ORACLE.EXE (M000) MMON_SLAVE KDILM background EXEcution 29-7? -13 08.23.38.681000000 ?? ORACLE.EXE (M002) MMON_SLAVE KDILM background EXEcution 29-7? -13 08.32.38.968000000 ?? ORACLE.EXE (M000) MMON_SLAVE KDILM background EXEcution 29-7? -13 08.33.39.993000000 ?? ORACLE.EXE (M003) MMON_SLAVE KDILM background EXEcution 29-7? -13 08.33.40.993000000 ?? ORACLE.EXE (M003) MMON_SLAVE KDILM background EXEcution 29-7? -13 08.36.40.066000000 ?? ORACLE.EXE (M000) MMON_SLAVE KDILM background EXEcution 29-7? -13 08.37.42.258000000 ?? ORACLE.EXE (M000) MMON_SLAVE KDILM background EXEcution 29-7? -13 08.37.43.258000000 ?? ORACLE.EXE (M000) MMON_SLAVE KDILM background EXEcution 29-7? -13 08.37.44.258000000 ?? ORACLE.EXE (M000) MMON_SLAVE KDILM background EXEcution 29-7? -13 08.38.42.386000000 ?? ORACLE.EXE (M001) MMON_SLAVE KDILM background EXEcution select distinct action from v$active_session_history where action like 'KDILM%' KDILM background CLeaNup KDILM background EXEcution SQL> execute set_window('MONDAY_WINDOW','CLOSE'); Set Maint. Window CLOSE ----------------------------- Window Name : MONDAY_WINDOW Enabled? : TRUE Active? : FALSE ----------------------------- PL/SQL ???????? SQL> drop table employee purge ; ????? ???? ????? spool ilm_usecase_1_cleanup.lst @ilm_demo_cleanup ; spool off

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  • How to set MinWorkingSet and MaxWorkingSet in a 64-bit .NET process?

    - by Gravitas
    How do I set MinWorkingSet and MaxWorking set for a 64-bit .NET process? p.s. I can set the MinWorkingSet and MaxWorking set for a 32-bit process, as follows: [DllImport("KERNEL32.DLL", EntryPoint = "SetProcessWorkingSetSize", SetLastError = true, CallingConvention = CallingConvention.StdCall)] internal static extern bool SetProcessWorkingSetSize(IntPtr pProcess, int dwMinimumWorkingSetSize, int dwMaximumWorkingSetSize); [DllImport("KERNEL32.DLL", EntryPoint = "GetCurrentProcess", SetLastError = true, CallingConvention = CallingConvention.StdCall)] internal static extern IntPtr MyGetCurrentProcess(); // In main(): SetProcessWorkingSetSize(Process.GetCurrentProcess().Handle, int.MaxValue, int.MaxValue); Update: Unfortunately, even if we do this call, the garbage collection trims the working set down anyway, bypassing MinWorkingSet (see "Automatic GC.Collect() in the diagram below). Question: Is there a way to lock the WorkingSet (the green line) to 1GB, to avoid the spike in page faults (the red lines) that occur when allocating new memory into the process? p.s. Every time a page fault occurs, it blocks the thread for 250us, which hits application performance badly.

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  • Problem running iPhone application on iPhone from Xcode (and in Instruments)

    - by Ben
    Hi I have a problem running one application on the iPhone from Xcode (or Instruments). When I try to run the app I get the error message Failed to upload XXX.app in the bottom left corner of Xcode. The strange thing is it actually uploaded the app to the iPhone but it doesn't start it (after this I can start the app by hand on the iPhone). So without being able to start the app from Xcode or instruments I have no chance of debugging/performance testing. Any advice on what might be going wrong here? The iPhone console shows me this: Thu Oct 1 14:25:18 unknown mobile_installationd[1976] <Error>: 00808e00 install_embedded_profile: Skipping the installation of the embedded profile Thu Oct 1 14:25:23 unknown SpringBoard[25] <Warning>: Reloading and rendering all application icons. Other applications work fine. I've tried this on two iPhones (both 3.1) with the same result. I am running Xcode 3.2 on SnowLeopard. Regards

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  • ASP.Net Authentication with MVC2--how to integrate with DB?

    - by alchemical
    I'm trying to understand the authentication section sample project that opens in a new MVC2 project in VS2010. It essentially lets you register, login, etc. I looked through the code that implements this briefly, it looked fairly complicated. (10 tables, 40 sprocs, 10 views, 4 models, 1 model, 1 controller, etc.) Is it best to utilize this provided framework for authentication? If so, how would I integrate this with my own database models (which has user and role tables, etc.). Also, if I use their framework, are there any performance issues at higher traffic volumes (like SO for example), do I need to become responsible for maintaining the authentication DB as well in this case?

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  • Help with Design for Vacation Tracking System (C#/.NET/Access/WebServices/SOA/Excel) [closed]

    - by Aaronaught
    I have been tasked with developing a system for tracking our company's paid time-off (vacation, sick days, etc.) At the moment we are using an Excel spreadsheet on a shared network drive, and it works pretty well, but we are concerned that we won't be able to "trust" employees forever and sometimes we run into locking issues when two people try to open the spreadsheet at once. So we are trying to build something a little more robust. I would like some input on this design in terms of maintainability, scalability, extensibility, etc. It's a pretty simple workflow we need to represent right now: I started with a basic MS Access schema like this: Employees (EmpID int, EmpName varchar(50), AllowedDays int) Vacations (VacationID int, EmpID int, BeginDate datetime, EndDate datetime) But we don't want to spend a lot of time building a schema and database like this and have to change it later, so I think I am going to go with something that will be easier to expand through configuration. Right now the vacation table has this schema: Vacations (VacationID int, PropName varchar(50), PropValue varchar(50)) And the table will be populated with data like this: VacationID | PropName | PropValue -----------+--------------+------------------ 1 | EmpID | 4 1 | EmpName | James Jones 1 | Reason | Vacation 1 | BeginDate | 2/24/2010 1 | EndDate | 2/30/2010 1 | Destination | Spectate Swamp 2 | ... | ... I think this is a pretty good, extensible design, we can easily add new properties to the vacation like the destination or maybe approval status, etc. I wasn't too sure how to go about managing the database of valid properties, I thought of putting them in a separate PropNames table but it gets complicated to manage all the different data types and people say that you shouldn't put CLR type names into a SQL database, so I decided to use XML instead, here is the schema: <VacationProperties> <PropertyNames>EmpID,EmpName,Reason,BeginDate,EndDate,Destination</PropertyNames> <PropertyTypes>System.Int32,System.String,System.String,System.DateTime,System.DateTime,System.String</PropertyTypes> <PropertiesRequired>true,true,false,true,true,false</PropertiesRequired> </VacationProperties> I might need more fields than that, I'm not completely sure. I'm parsing the XML like this (would like some feedback on the parsing code): string xml = File.ReadAllText("properties.xml"); Match m = Regex.Match(xml, "<(PropertyNames)>(.*?)</PropertyNames>"; string[] pn = m.Value.Split(','); // do the same for PropertyTypes, PropertiesRequired Then I use the following code to persist configuration changes to the database: string sql = "DROP TABLE VacationProperties"; sql = sql + " CREATE TABLE VacationProperties "; sql = sql + "(PropertyName varchar(100), PropertyType varchar(100) "; sql = sql + "IsRequired varchar(100))"; for (int i = 0; i < pn.Length; i++) { sql = sql + " INSERT VacationProperties VALUES (" + pn[i] + "," + pt[i] + "," + pv[i] + ")"; } // GlobalConnection is a singleton new SqlCommand(sql, GlobalConnection.Instance).ExecuteReader(); So far so good, but after a few days of this I then realized that a lot of this was just a more specific kind of a generic workflow which could be further abstracted, and instead of writing all of this boilerplate plumbing code I could just come up with a workflow and plug it into a workflow engine like Windows Workflow Foundation and have the users configure it: In order to support routing these configurations throw the workflow system, it seemed natural to implement generic XML Web Services for this instead of just using an XML file as above. I've used this code to implement the Web Services: public class VacationConfigurationService : WebService { [WebMethod] public void UpdateConfiguration(string xml) { // Above code goes here } } Which was pretty easy, although I'm still working on a way to validate that XML against some kind of schema as there's no error-checking yet. I also created a few different services for other operations like VacationSubmissionService, VacationReportService, VacationDataService, VacationAuthenticationService, etc. The whole Service Oriented Architecture looks like this: And because the workflow itself might change, I have been working on a way to integrate the WF workflow system with MS Visio, which everybody at the office already knows how to use so they could make changes pretty easily. We have a diagram that looks like the following (it's kind of hard to read but the main items are Activities, Authenticators, Validators, Transformers, Processors, and Data Connections, they're all analogous to the services in the SOA diagram above). The requirements for this system are: (Note - I don't control these, they were given to me by management) Main workflow must interface with Excel spreadsheet, probably through VBA macros (to ease the transition to the new system) Alerts should integrate with MS Outlook, Lotus Notes, and SMS (text messages). We also want to interface it with the company Voice Mail system but that is not a "hard" requirement. Performance requirements: Must handle 250,000 Transactions Per Second Should be able to handle up to 20,000 employees (right now we have 3) 99.99% uptime ("four nines") expected Must be secure against outside hacking, but users cannot be required to enter a username/password. Platforms: Must support Windows XP/Vista/7, Linux, iPhone, Blackberry, DOS 2.0, VAX, IRIX, PDP-11, Apple IIc. Time to complete: 6 to 8 weeks. My questions are: Is this a good design for the system so far? Am I using all of the recommended best practices for these technologies? How do I integrate the Visio diagram above with the Windows Workflow Foundation to call the ConfigurationService and persist workflow changes? Am I missing any important components? Will this be extensible enough to support any scenario via end-user configuration? Will the system scale to the above performance requirements? Will we need any expensive hardware to run it? Are there any "gotchas" I should know about with respect to cross-platform compatibility? For example would it be difficult to convert this to an iPhone app? How long would you expect this to take? (We've dedicated 1 week for testing so I'm thinking maybe 5 weeks?) Many thanks for your advices, Aaron

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  • how can I code a recursive query in an Entity Framework model?

    - by Greg
    Hi, I have a model which includes NODES, and RELATIONSHIPS (that tie the nodes together, via a parent_node, child_node arrangement). Q1 - Is there any way in EF / Linq-to-entities to perform a query on nodes (e.g. context.Nodes..) to find say "all parents" or "or children" in the graph? Q2 - If there's not in Linq-to-entities, is there any other way to do this other than writing a method that manually goes through and doing it? Q3 - If manual is the only way to do it, should I be concerned about the number of database hits that will be going out to the database as the method keeps recursing through the data? Or more specifically, is there any EF caching type feature that might assist here in ensuring the method is performance from a "number of database hits" point of view? thanks thanks

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  • Software Engineering undergraduate project ideas

    - by Nasser Hajloo
    There was a similar post at << Computer science undergraduate project ideas << Ideas for Software Engineering Thesis Project << Senior computer engineering project ideas ? << Final Year Project(Software Engineering) Idea So I read all of them and my answer wasn't fit to those. Actually I'm looking for some ideas which 1 - Help me extend a functionality of Open source software (like creating a usefull add-in 2 - Let me Create a Scientific Paper (ideas to publish a scientific paper) 3 - Or Create a Unique an usefull application from the scratch , (like performance tool, profiler, analyzers and other similar tools) I know C# - Asp.net and sql So with all these conditions what do you think is better to do? let me know your ideas whatever those are. any idea appriciated.

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  • ASP.NET MVC 2 disable cache for browser back button in partial views

    - by brainnovative
    I am using Html.RenderAction<CartController>(c => c.Show()); on my master Page to display the cart for all pages. The problem is when I add an item to the cart and then hit the browser back button. It shows the old cart (from Cache) until I hit the refresh button or navigate to another page. I've tried this and it works perfectly but it disables the Cache globally for the whole page an for all pages in my site (since this Action method is used on the master page). I need to enable cache for several other partial views (action methods) for performance reasons. I wouldn't like to use client side script with AJAX to refresh the cart (and login view) on page load - but that's the only solution I can think of right now. Does anyone know better?

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  • Problem setting up Master-Master Replication in MySQL

    - by Andrew
    I am attempting to setup Master-Master Replication on two MySQL database servers. I have followed the steps in this guide, but it fails in the middle of Step 4 with SHOW MASTER STATUS; It simply returns an empty set. I get the same 3 errors in both servers' logs. MySQL errors on SQL1: [ERROR] Failed to open the relay log './sql1-relay-bin.000001' (relay_log_pos 4) [ERROR] Could not find target log during relay log initialization [ERROR] Failed to initialize the master info structure MySQL Errors on SQL2: [ERROR] Failed to open the relay log './sql2-relay-bin.000001' (relay_log_pos 4) [ERROR] Could not find target log during relay log initialization [ERROR] Failed to initialize the master info structure The errors make no sense because I'm not referencing those files in any of my configurations. I'm using Ubuntu Server 10.04 x64 and my configuration files are copied below. I don't know where to go from here or how to troubleshoot this. Please help. Thanks. /etc/mysql/my.cnf on SQL1: # # The MySQL database server configuration file. # # You can copy this to one of: # - "/etc/mysql/my.cnf" to set global options, # - "~/.my.cnf" to set user-specific options. # # One can use all long options that the program supports. # Run program with --help to get a list of available options and with # --print-defaults to see which it would actually understand and use. # # For explanations see # http://dev.mysql.com/doc/mysql/en/server-system-variables.html # This will be passed to all mysql clients # It has been reported that passwords should be enclosed with ticks/quotes # escpecially if they contain "#" chars... # Remember to edit /etc/mysql/debian.cnf when changing the socket location. [client] port = 3306 socket = /var/run/mysqld/mysqld.sock # Here is entries for some specific programs # The following values assume you have at least 32M ram # This was formally known as [safe_mysqld]. Both versions are currently parsed. [mysqld_safe] socket = /var/run/mysqld/mysqld.sock nice = 0 [mysqld] # # * Basic Settings # # # * IMPORTANT # If you make changes to these settings and your system uses apparmor, you may # also need to also adjust /etc/apparmor.d/usr.sbin.mysqld. # user = mysql socket = /var/run/mysqld/mysqld.sock port = 3306 basedir = /usr datadir = /var/lib/mysql tmpdir = /tmp skip-external-locking # # Instead of skip-networking the default is now to listen only on # localhost which is more compatible and is not less secure. bind-address = <SQL1's IP> # # * Fine Tuning # key_buffer = 16M max_allowed_packet = 16M thread_stack = 192K thread_cache_size = 8 # This replaces the startup script and checks MyISAM tables if needed # the first time they are touched myisam-recover = BACKUP #max_connections = 100 #table_cache = 64 #thread_concurrency = 10 # # * Query Cache Configuration # query_cache_limit = 1M query_cache_size = 16M # # * Logging and Replication # # Both location gets rotated by the cronjob. # Be aware that this log type is a performance killer. # As of 5.1 you can enable the log at runtime! #general_log_file = /var/log/mysql/mysql.log #general_log = 1 log_error = /var/log/mysql/error.log # Here you can see queries with especially long duration #log_slow_queries = /var/log/mysql/mysql-slow.log #long_query_time = 2 #log-queries-not-using-indexes # # The following can be used as easy to replay backup logs or for replication. # note: if you are setting up a replication slave, see README.Debian about # other settings you may need to change. server-id = 1 replicate-same-server-id = 0 auto-increment-increment = 2 auto-increment-offset = 1 master-host = <SQL2's IP> master-user = slave_user master-password = "slave_password" master-connect-retry = 60 replicate-do-db = db1 log-bin= /var/log/mysql/mysql-bin.log binlog-do-db = db1 binlog-ignore-db = mysql relay-log = /var/lib/mysql/slave-relay.log relay-log-index = /var/lib/mysql/slave-relay-log.index expire_logs_days = 10 max_binlog_size = 500M # # * InnoDB # # InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/. # Read the manual for more InnoDB related options. There are many! # # * Security Features # # Read the manual, too, if you want chroot! # chroot = /var/lib/mysql/ # # For generating SSL certificates I recommend the OpenSSL GUI "tinyca". # # ssl-ca=/etc/mysql/cacert.pem # ssl-cert=/etc/mysql/server-cert.pem # ssl-key=/etc/mysql/server-key.pem [mysqldump] quick quote-names max_allowed_packet = 16M [mysql] #no-auto-rehash # faster start of mysql but no tab completition [isamchk] key_buffer = 16M # # * IMPORTANT: Additional settings that can override those from this file! # The files must end with '.cnf', otherwise they'll be ignored. # !includedir /etc/mysql/conf.d/ /etc/mysql/my.cnf on SQL2: # # The MySQL database server configuration file. # # You can copy this to one of: # - "/etc/mysql/my.cnf" to set global options, # - "~/.my.cnf" to set user-specific options. # # One can use all long options that the program supports. # Run program with --help to get a list of available options and with # --print-defaults to see which it would actually understand and use. # # For explanations see # http://dev.mysql.com/doc/mysql/en/server-system-variables.html # This will be passed to all mysql clients # It has been reported that passwords should be enclosed with ticks/quotes # escpecially if they contain "#" chars... # Remember to edit /etc/mysql/debian.cnf when changing the socket location. [client] port = 3306 socket = /var/run/mysqld/mysqld.sock # Here is entries for some specific programs # The following values assume you have at least 32M ram # This was formally known as [safe_mysqld]. Both versions are currently parsed. [mysqld_safe] socket = /var/run/mysqld/mysqld.sock nice = 0 [mysqld] # # * Basic Settings # # # * IMPORTANT # If you make changes to these settings and your system uses apparmor, you may # also need to also adjust /etc/apparmor.d/usr.sbin.mysqld. # user = mysql socket = /var/run/mysqld/mysqld.sock port = 3306 basedir = /usr datadir = /var/lib/mysql tmpdir = /tmp skip-external-locking # # Instead of skip-networking the default is now to listen only on # localhost which is more compatible and is not less secure. bind-address = <SQL2's IP> # # * Fine Tuning # key_buffer = 16M max_allowed_packet = 16M thread_stack = 192K thread_cache_size = 8 # This replaces the startup script and checks MyISAM tables if needed # the first time they are touched myisam-recover = BACKUP #max_connections = 100 #table_cache = 64 #thread_concurrency = 10 # # * Query Cache Configuration # query_cache_limit = 1M query_cache_size = 16M # # * Logging and Replication # # Both location gets rotated by the cronjob. # Be aware that this log type is a performance killer. # As of 5.1 you can enable the log at runtime! #general_log_file = /var/log/mysql/mysql.log #general_log = 1 log_error = /var/log/mysql/error.log # Here you can see queries with especially long duration #log_slow_queries = /var/log/mysql/mysql-slow.log #long_query_time = 2 #log-queries-not-using-indexes # # The following can be used as easy to replay backup logs or for replication. # note: if you are setting up a replication slave, see README.Debian about # other settings you may need to change. server-id = 2 replicate-same-server-id = 0 auto-increment-increment = 2 auto-increment-offset = 2 master-host = <SQL1's IP> master-user = slave_user master-password = "slave_password" master-connect-retry = 60 replicate-do-db = db1 log-bin= /var/log/mysql/mysql-bin.log binlog-do-db = db1 binlog-ignore-db = mysql relay-log = /var/lib/mysql/slave-relay.log relay-log-index = /var/lib/mysql/slave-relay-log.index expire_logs_days = 10 max_binlog_size = 500M # # * InnoDB # # InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/. # Read the manual for more InnoDB related options. There are many! # # * Security Features # # Read the manual, too, if you want chroot! # chroot = /var/lib/mysql/ # # For generating SSL certificates I recommend the OpenSSL GUI "tinyca". # # ssl-ca=/etc/mysql/cacert.pem # ssl-cert=/etc/mysql/server-cert.pem # ssl-key=/etc/mysql/server-key.pem [mysqldump] quick quote-names max_allowed_packet = 16M [mysql] #no-auto-rehash # faster start of mysql but no tab completition [isamchk] key_buffer = 16M # # * IMPORTANT: Additional settings that can override those from this file! # The files must end with '.cnf', otherwise they'll be ignored. # !includedir /etc/mysql/conf.d/

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  • CUDA Driver API vs. CUDA runtime

    - by Morten Christiansen
    When writing CUDA applications, you can either work at the driver level or at the runtime level as illustrated on this image (The libraries are CUFFT and CUBLAS for advanced math): I assume the tradeoff between the two are increased performance for the low-evel API but at the cost of increased complexity of code. What are the concrete differences and are there any significant things which you cannot do with the high-level API? I am using CUDA.net for interop with C# and it is built as a copy of the driver API. This encourages writing a lot of rather complex code in C# while the C++ equivalent would be more simple using the runtime API. Is there anything to win by doing it this way? The one benefit I can see is that it is easier to integrate intelligent error handling with the rest of the C# code.

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  • Is SiteCore slow and buggy?

    - by Larsenal
    I've seen plenty of negative comments regarding performance and general bugginess. However, to be fair, most of these look like they were within the v5.3 timeframe. Have they fixed all of those issues in v6.0? Is it an excellent product? Some examples of the complaints: Maybe it’s just a case of user error, but this guy says, “some pages take as much as 20s to render…” Source Here, in the comments, one fellow remaks, “Sitecore backend is incredible slow. Sitecore developement is really pain, it takes from 2 minutes to start sitecore and many many seconds to do small backend operations. They claim to have a quick client, but that is a BIG LIE. All developers in my company really hate sitecore for being so slow.” Source Another search yielded, “Sitecore’s users listed three issues as number one: licensing, the server as a resource hog, and the site’s slow responsiveness.” Source

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  • ASP.NET AJAX ToolkitScriptManager Issue With Combining Scripts

    - by Kumar
    I have an ASP.NET 3.5 web application in which i am using the ToolkitScriptManager as below: <ajaxToolkit:ToolkitScriptManager ID="ToolkitScriptManager1" EnablePageMethods="true" ScriptMode="Release" LoadScriptsBeforeUI="false" runat="server" CombineScripts="false"> <CompositeScript> <Scripts> <asp:ScriptReference Path="~/JavaScript/jquery-1.4.1.min.js" /> <asp:ScriptReference Path="~/JavaScript/Validators.js" /> </Scripts> </CompositeScript> </ajaxToolkit:ToolkitScriptManager> This works fine but from a performance standpoint this is not good as the pages are making a lot of requests to the webresources.axd and scriptresource.axd files. When I changed the CombineScripts property to true my ASP.NET AJAX control extenders are no longer working. What is the reason for this weired behavior and is there a fix for this?

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  • JSR-299 CDI / Weld vs. Google Guice

    - by deamon
    Weld, the JSR-299 Contexts and Dependency Injection reference implementation, considers itself as a kind of successor of Spring and Guice. CDI was influenced by a number of existing Java frameworks, including Seam, Guice and Spring. However, CDI has its own, very distinct, character: more typesafe than Seam, more stateful and less XML-centric than Spring, more web and enterprise-application capable than Guice. But it couldn't have been any of these without inspiration from the frameworks mentioned and lots of collaboration and hard work by the JSR-299 Expert Group (EG). http://docs.jboss.org/weld/reference/latest/en-US/html/1.html What makes Weld more capable for enterprise application compared to Guice? Are there any advantages or disadvantages compared to Guice? What do you think about Guice AOP compared to Weld interceptors? What about performance?

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  • Compiled Linq & String.Contains

    - by sharru
    i'm using linq-to-sql and i'm use complied linq for better performance. I have a users table with a INT field called "LookingFor" that can have the following values.1,2,3,12,123,13,23. I wrote a query to return the users based on the "lookingFor" column i want to return all users that contains the "lookingFor" value (not only those equal to it). In example if user.LookingFor = 12 , and query paramter is 1 this user should be selected. private static Func<NeDataContext, int, IQueryable<int>> MainSearchQuery = CompiledQuery.Compile((NeDataContext db, int lookingFor) => (from u in db.Users where (lookingFor == -1 ? true : u.LookingFor.ToString().Contains(lookingFor) select u.username); This WORKS on non complied linq but throws error when using complied. How do i fix it to work using complied linq? I get this error: Only arguments that can be evaluated on the client are supported for the String.Contains method.

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  • Search algorithm (with a sort algorithm already implemented)

    - by msr
    Hello, Im doing a Java application and Im facing some doubts in which concerns performance. I have a PriorityQueue which guarantees me the element removed is the one with greater priority. That PriorityQueue has instances of class Event (which implements Comparable interface). Each Event is associated with a Entity. The size of that priorityqueue could be huge and very frequently I will have to remove events associated to an entity. Right now Im using an iterator to run all the priorityqueue. However Im finding it heavy and I wonder if there are better alternatives to search and remove events associated with an entity "xpto". Any suggestions? Thanks!

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  • ListView items not clickable with HorizontalScrollView inside

    - by Felix
    I have quite a complicated ListView. Each item looks something like this: > LinearLayout (vertical) > LinearLayout (horizontal) > include (horizontal LinearLayout with two TextViews) > include (ditto) > include (ditto) > TextView > HorizontalScrollView (this guy is my problem) > LinearLayout (horizontal) In my activity, when an item is created (getView() is called) I add dynamic TextViews to the LinearLayout inside the HorizontalScrollView (besides filling the other, simpler stuff out). Amazingly, performance is pretty good. My problem is that when I added the HorizontalScrollView, my list items became unclickable. They don't get the orange background when clicked and they don't fire the OnItemClickedListener I have set up (to do a simple Log.d call). How can I make my list items clickable again?

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  • node.js on multi-core machines

    - by zaharpopov
    node.js looks interesting BUT... I must miss something - isn't node.js tuned only to run on a single process & thread? Then how does it scale for multi-core CPUs and multi-CPU servers? After all, it is all great to make fast as possible single-thread server, but for high loads I would want to use several CPUs. And the same goes for making applications faster - seems today the way is use multiple CPUs and parallelize the tasks. How does node.js fit into this picture? Is its idea to somehow distribute multiple instances or what?

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  • Using Image Source with big images in WPF

    - by xyzzer
    I am working on an application that allows users to manipulate multiple images by using ItemsControl. I started running some tests and found that the app has problems displaying some big images - ie. it did not work with the high resolution (21600x10800), 20MB images from http://earthobservatory.nasa.gov/Features/BlueMarble/BlueMarble_monthlies.php, though it displays the 6200x6200, 60MB Hubble telescope image from http://zebu.uoregon.edu/hudf/hudf.jpg just fine. The original solution just specified an Image control with a Source property pointing at a file on a disk (through a binding). With the Blue Marble file - the image would just not show up. Now this could be just a bug hidden somewhere deep in the funky MVVM + XAML implementation - the visual tree displayed by Snoop goes like: Window/Border/AdornerDecorator/ContentPresenter/Grid/Canvas/UserControl/Border/ContentPresenter/Grid/Grid/Grid/Grid/Border/Grid/ContentPresenter/UserControl/UserControl/Border/ContentPresenter/Grid/Grid/Grid/Grid/Viewbox/ContainerVisual/UserControl/Border/ContentPresenter/Grid/Grid/ItemsControl/Border/ItemsPresenter/Canvas/ContentPresenter/Grid/Grid/ContentPresenter/Image... Now debug this! WPF can be crazy like that... Anyway, it turned out that if I create a simple WPF application - the images load just fine. I tried finding out the root cause, but I don't want to spend weeks on it. I figured the right thing to do might be to use a converter to scale the images down - this is what I have done: ImagePath = @"F:\Astronomical\world.200402.3x21600x10800.jpg"; TargetWidth = 2800; TargetHeight = 1866; and <Image> <Image.Source> <MultiBinding Converter="{StaticResource imageResizingConverter}"> <MultiBinding.Bindings> <Binding Path="ImagePath"/> <Binding RelativeSource="{RelativeSource Self}" /> <Binding Path="TargetWidth"/> <Binding Path="TargetHeight"/> </MultiBinding.Bindings> </MultiBinding> </Image.Source> </Image> and public class ImageResizingConverter : MarkupExtension, IMultiValueConverter { public Image TargetImage { get; set; } public string SourcePath { get; set; } public int DecodeWidth { get; set; } public int DecodeHeight { get; set; } public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture) { this.SourcePath = values[0].ToString(); this.TargetImage = (Image)values[1]; this.DecodeWidth = (int)values[2]; this.DecodeHeight = (int)values[3]; return DecodeImage(); } private BitmapImage DecodeImage() { BitmapImage bi = new BitmapImage(); bi.BeginInit(); bi.DecodePixelWidth = (int)DecodeWidth; bi.DecodePixelHeight = (int)DecodeHeight; bi.UriSource = new Uri(SourcePath); bi.EndInit(); return bi; } public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture) { throw new Exception("The method or operation is not implemented."); } public override object ProvideValue(IServiceProvider serviceProvider) { return this; } } Now this works fine, except for one "little" problem. When you just specify a file path in Image.Source - the application actually uses less memory and works faster than if you use BitmapImage.DecodePixelWidth. Plus with Image.Source if you have multiple Image controls that point to the same image - they only use as much memory as if only one image was loaded. With the BitmapImage.DecodePixelWidth solution - each additional Image control uses more memory and each of them uses more than when just specifying Image.Source. Perhaps WPF somehow caches these images in compressed form while if you specify the decoded dimensions - it feels like you get an uncompressed image in memory, plus it takes 6 times the time (perhaps without it the scaling is done on the GPU?), plus it feels like the original high resolution image also gets loaded and takes up space. If I just scale the image down, save it to a temporary file and then use Image.Source to point at the file - it will probably work, but it will be pretty slow and it will require handling cleanup of the temporary file. If I could detect an image that does not get loaded properly - maybe I could only scale it down if I need to, but Image.ImageFailed never gets triggered. Maybe it has something to do with the video memory and this app just using more of it with the deep visual tree, opacity masks etc. Actual question: How can I load big images as quickly as Image.Source option does it, without using more memory for additional copies and additional memory for the scaled down image if I only need them at a certain resolution lower than original? Also, I don't want to keep them in memory if no Image control is using them anymore.

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  • Asp.net ADO.NET Entity Framework or ADO.NET

    - by sharru
    I'm starting a new project based on ASP.NET and Windows server. The application is planned to be pretty big and serve large amount of clients pulling and updating high freq. changing data. I have previously created projects with Linq-To-Sql or with Ado.Net. My plan for this project is to use VS2010 and the new EF4 framework. It would be great to hear other programmers options about development with Entity Framework Pros and cons from previous experience? Do you think EF4 is ready for production? Should i take the risk or just stick with plain old good ADO.NET?

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  • Where are the Entity Framework t4 templates for Data Annotations?

    - by JK
    I have been googling this non stop for 2 days now and can't find a single complete, ready to use, fully implemented t4 template that generates DataAnnotations. Do they even exist? I generate POCOs with the standard t4 templates. The actual database table has metadata that describes some of the validation rules, eg not null, nvarchar(25), etc. So all I want is a t4 template that can take my table and generate a POCO with DataAnnotations, eg public class Person { [Required] [StringLength(255)] public FirstName {get;set} } It is a basic and fundamental requirement, surely I can not be the first person in the entire world to have this requirement? I don't want to re-invent the wheel here. Yet I haven't found it after search high and low for days. This must be possible (and hopefully must be available somewhere to just download) - it would be criminally wrong to have to manually type in these annotations when the metadata for them already exists in the database.

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  • How do I prevent flickering on CListCtrl?

    - by Sorin Sbarnea
    I'm using a CListCtrl/CListView report view (LVS_REPORT) in virtual mode (LVS_OWNERDATA) with LVS_EX_DOUBLEBUFFER enabled and I encounter ugly flickering. Double buffer have a real effect but it doesn't stop all flickering (without it very slow). I'm not looking for switching to other controls that would require a high amount of rework (like ObjectListView) How does the flickering behaves: * on column resize - the background is first clean using lightgray and after this is displayed the text (background is white) * on mouse scroll (animated) - for a very short time there is lightgray-bar displayed in the area where new lines are to be displayed. It looks like it does clean the background using the default window background color (lightgray) for the area where it has to redraw. How do I solve the flickering problem?

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  • Method 'SingleOrDefault' not supported by Linq to Entities

    - by user300992
    I read other posts on similar problem on using SingleOfDefault on Linq-To-Entity, some suggested using "First()" and some others suggested using "Extension" method to implement the Single(). This code throws exception: Movie movie = (from a in movies where a.MovieID == '12345' select a).SingleOrDefault(); If I convert the object query to a List using .ToList(), "SingleOrDefault()" actually works perfectly without throwing any error. My question is: Is it not good to convert to List? Is it going to be performance issue for more complicated queries? What does it get translated in SQL? Movie movie = (from a in movies.ToList() where a.MovieID == '12345' select a).SingleOrDefault();

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