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  • Pain Comes Instantly

    - by user701213
    When I look back at recent blog entries – many of which are not all that current (more on where my available writing time is going later) – I am struck by how many of them focus on public policy or legislative issues instead of, say, the latest nefarious cyberattack or exploit (or everyone’s favorite new pastime: coining terms for the Coming Cyberpocalypse: “digital Pearl Harbor” is so 1941). Speaking of which, I personally hope evil hackers from Malefactoria will someday hack into my bathroom scale – which in a future time will be connected to the Internet because, gosh, wouldn’t it be great to have absolutely everything in your life Internet-enabled? – and recalibrate it so I’m 10 pounds thinner. The horror. In part, my focus on public policy is due to an admitted limitation of my skill set. I enjoy reading technical articles about exploits and cybersecurity trends, but writing a blog entry on those topics would take more research than I have time for and, quite honestly, doesn’t play to my strengths. The first rule of writing is “write what you know.” The bigger contributing factor to my recent paucity of blog entries is that more and more of my waking hours are spent engaging in “thrust and parry” activity involving emerging regulations of some sort or other. I’ve opined in earlier blogs about what constitutes good and reasonable public policy so nobody can accuse me of being reflexively anti-regulation. That said, you have so many cycles in the day, and most of us would rather spend it slaying actual dragons than participating in focus groups on whether dragons are really a problem, whether lassoing them (with organic, sustainable and recyclable lassos) is preferable to slaying them – after all, dragons are people, too - and whether we need lasso compliance auditors to make sure lassos are being used correctly and humanely. (A point that seems to evade many rule makers: slaying dragons actually accomplishes something, whereas talking about “approved dragon slaying procedures and requirements” wastes the time of those who are competent to dispatch actual dragons and who were doing so very well without the input of “dragon-slaying theorists.”) Unfortunately for so many of us who would just get on with doing our day jobs, cybersecurity is rapidly devolving into the “focus groups on dragon dispatching” realm, which actual dragons slayers have little choice but to participate in. The general trend in cybersecurity is that powers-that-be – which encompasses groups other than just legislators – are often increasingly concerned and therefore feel they need to Do Something About Cybersecurity. Many seem to believe that if only we had the right amount of regulation and oversight, there would be no data breaches: a breach simply must mean Someone Is At Fault and Needs Supervision. (Leaving aside the fact that we have lots of home invasions despite a) guard dogs b) liberal carry permits c) alarm systems d) etc.) Also note that many well-managed and security-aware organizations, like the US Department of Defense, still get hacked. More specifically, many powers-that-be feel they must direct industry in a multiplicity of ways, up to and including how we actually build and deploy information technology systems. The more prescriptive the requirement, the more regulators or overseers a) can be seen to be doing something b) feel as if they are doing something regardless of whether they are actually doing something useful or cost effective. Note: an unfortunate concomitant of Doing Something is that often the cure is worse than the ailment. That is, doing what overseers want creates unfortunate byproducts that they either didn’t foresee or worse, don’t care about. After all, the logic goes, we Did Something. Prescriptive practice in the IT industry is problematic for a number of reasons. For a start, prescriptive guidance is really only appropriate if: • It is cost effective• It is “current” (meaning, the guidance doesn’t require the use of the technical equivalent of buggy whips long after horse-drawn transportation has become passé)*• It is practical (that is, pragmatic, proven and effective in the real world, not theoretical and unproven)• It solves the right problem With the above in mind, heading up the list of “you must be joking” regulations are recent disturbing developments in the Payment Card Industry (PCI) world. I’d like to give PCI kahunas the benefit of the doubt about their intentions, except that efforts by Oracle among others to make them aware of “unfortunate side effects of your requirements” – which is as tactful I can be for reasons that I believe will become obvious below - have gone, to-date, unanswered and more importantly, unchanged. A little background on PCI before I get too wound up. In 2008, the Payment Card Industry (PCI) Security Standards Council (SSC) introduced the Payment Application Data Security Standard (PA-DSS). That standard requires vendors of payment applications to ensure that their products implement specific requirements and undergo security assessment procedures. In order to have an application listed as a Validated Payment Application (VPA) and available for use by merchants, software vendors are required to execute the PCI Payment Application Vendor Release Agreement (VRA). (Are you still with me through all the acronyms?) Beginning in August 2010, the VRA imposed new obligations on vendors that are extraordinary and extraordinarily bad, short-sighted and unworkable. Specifically, PCI requires vendors to disclose (dare we say “tell all?”) to PCI any known security vulnerabilities and associated security breaches involving VPAs. ASAP. Think about the impact of that. PCI is asking a vendor to disclose to them: • Specific details of security vulnerabilities • Including exploit information or technical details of the vulnerability • Whether or not there is any mitigation available (as in a patch) PCI, in turn, has the right to blab about any and all of the above – specifically, to distribute all the gory details of what is disclosed - to the PCI SSC, qualified security assessors (QSAs), and any affiliate or agent or adviser of those entities, who are in turn permitted to share it with their respective affiliates, agents, employees, contractors, merchants, processors, service providers and other business partners. This assorted crew can’t be more than, oh, hundreds of thousands of entities. Does anybody believe that several hundred thousand people can keep a secret? Or that several hundred thousand people are all equally trustworthy? Or that not one of the people getting all that information would blab vulnerability details to a bad guy, even by accident? Or be a bad guy who uses the information to break into systems? (Wait, was that the Easter Bunny that just hopped by? Bringing world peace, no doubt.) Sarcasm aside, common sense tells us that telling lots of people a secret is guaranteed to “unsecret” the secret. Notably, being provided details of a vulnerability (without a patch) is of little or no use to companies running the affected application. Few users have the technological sophistication to create a workaround, and even if they do, most workarounds break some other functionality in the application or surrounding environment. Also, given the differences among corporate implementations of any application, it is highly unlikely that a single workaround is going to work for all corporate users. So until a patch is developed by the vendor, users remain at risk of exploit: even more so if the details of vulnerability have been widely shared. Sharing that information widely before a patch is available therefore does not help users, and instead helps only those wanting to exploit known security bugs. There’s a shocker for you. Furthermore, we already know that insider information about security vulnerabilities inevitably leaks, which is why most vendors closely hold such information and limit dissemination until a patch is available (and frequently limit dissemination of technical details even with the release of a patch). That’s the industry norm, not that PCI seems to realize or acknowledge that. Why would anybody release a bunch of highly technical exploit information to a cast of thousands, whose only “vetting” is that they are members of a PCI consortium? Oracle has had personal experience with this problem, which is one reason why information on security vulnerabilities at Oracle is “need to know” (we use our own row level access control to limit access to security bugs in our bug database, and thus less than 1% of development has access to this information), and we don’t provide some customers with more information than others or with vulnerability information and/or patches earlier than others. Failure to remember “insider information always leaks” creates problems in the general case, and has created problems for us specifically. A number of years ago, one of the UK intelligence agencies had information about a non-public security vulnerability in an Oracle product that they circulated among other UK and Commonwealth defense and intelligence entities. Nobody, it should be pointed out, bothered to report the problem to Oracle, even though only Oracle could produce a patch. The vulnerability was finally reported to Oracle by (drum roll) a US-based commercial company, to whom the information had leaked. (Note: every time I tell this story, the MI-whatever agency that created the problem gets a bit shirty with us. I know they meant well and have improved their vulnerability handling/sharing processes but, dudes, next time you find an Oracle vulnerability, try reporting it to us first before blabbing to lots of people who can’t actually fix the problem. Thank you!) Getting back to PCI: clearly, these new disclosure obligations increase the risk of exploitation of a vulnerability in a VPA and thus, of misappropriation of payment card data and customer information that a VPA processes, stores or transmits. It stands to reason that VRA’s current requirement for the widespread distribution of security vulnerability exploit details -- at any time, but particularly before a vendor can issue a patch or a workaround -- is very poor public policy. It effectively publicizes information of great value to potential attackers while not providing compensating benefits - actually, any benefits - to payment card merchants or consumers. In fact, it magnifies the risk to payment card merchants and consumers. The risk is most prominent in the time before a patch has been released, since customers often have little option but to continue using an application or system despite the risks. However, the risk is not limited to the time before a patch is issued: customers often need days, or weeks, to apply patches to systems, based upon the complexity of the issue and dependence on surrounding programs. Rather than decreasing the available window of exploit, this requirement increases the available window of exploit, both as to time available to exploit a vulnerability and the ease with which it can be exploited. Also, why would hackers focus on finding new vulnerabilities to exploit if they can get “EZHack” handed to them in such a manner: a) a vulnerability b) in a payment application c) with exploit code: the “Hacking Trifecta!“ It’s fair to say that this is probably the exact opposite of what PCI – or any of us – would want. Established industry practice concerning vulnerability handling avoids the risks created by the VRA’s vulnerability disclosure requirements. Specifically, the norm is not to release information about a security bug until the associated patch (or a pretty darn good workaround) has been issued. Once a patch is available, the notice to the user community is a high-level communication discussing the product at issue, the level of risk associated with the vulnerability, and how to apply the patch. The notices do not include either the specific customers affected by the vulnerability or forensic reports with maps of the exploit (both of which are required by the current VRA). In this way, customers have the tools they need to prioritize patching and to help prevent an attack, and the information released does not increase the risk of exploit. Furthermore, many vendors already use industry standards for vulnerability description: Common Vulnerability Enumeration (CVE) and Common Vulnerability Scoring System (CVSS). CVE helps ensure that customers know which particular issues a patch addresses and CVSS helps customers determine how severe a vulnerability is on a relative scale. Industry already provides the tools customers need to know what the patch contains and how bad the problem is that the patch remediates. So, what’s a poor vendor to do? Oracle is reaching out to other vendors subject to PCI and attempting to enlist then in a broad effort to engage PCI in rethinking (that is, eradicating) these requirements. I would therefore urge all who care about this issue, but especially those in the vendor community whose applications are subject to PCI and who may not have know they were being asked to tell-all to PCI and put their customers at risk, to do one of the following: • Contact PCI with your concerns• Contact Oracle (we are looking for vendors to sign our statement of concern)• And make sure you tell your customers that you have to rat them out to PCI if there is a breach involving the payment application I like to be charitable and say “PCI meant well” but in as important a public policy issue as what you disclose about vulnerabilities, to whom and when, meaning well isn’t enough. We need to do well. PCI, as regards this particular issue, has not done well, and has compounded the error by thus far being nonresponsive to those of us who have labored mightily to try to explain why they might want to rethink telling the entire planet about security problems with no solutions. By Way of Explanation… Non-related to PCI whatsoever, and the explanation for why I have not been blogging a lot recently, I have been working on Other Writing Venues with my sister Diane (who has also worked in the tech sector, inflicting upgrades on unsuspecting and largely ungrateful end users). I am pleased to note that we have recently (self-)published the first in the Miss Information Technology Murder Mystery series, Outsourcing Murder. The genre might best be described as “chick lit meets geek scene.” Our sisterly nom de plume is Maddi Davidson and (shameless plug follows): you can order the paper version of the book on Amazon, or the Kindle or Nook versions on www.amazon.com or www.bn.com, respectively. From our book jacket: Emma Jones, a 20-something IT consultant, is working on an outsourcing project at Tahiti Tacos, a restaurant chain offering Polynexican cuisine: refried poi, anyone? Emma despises her boss Padmanabh, a brilliant but arrogant partner in GD Consulting. When Emma discovers His-Royal-Padness’s body (verdict: death by cricket bat), she becomes a suspect.With her overprotective family and her best friend Stacey providing endless support and advice, Emma stumbles her way through an investigation of Padmanabh’s murder, bolstered by fusion food feeding frenzies, endless cups of frou-frou coffee and serious surfing sessions. While Stacey knows a PI who owes her a favor, landlady Magda urges Emma to tart up her underwear drawer before the next cute cop with a search warrant arrives. Emma’s mother offers to fix her up with a PhD student at Berkeley and showers her with self-defense gizmos while her old lover Keoni beckons from Hawai’i. And everyone, even Shaun the barista, knows a good lawyer. Book 2, Denial of Service, is coming out this summer. * Given the rate of change in technology, today’s “thou shalts” are easily next year’s “buggy whip guidance.”

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  • AIX Checklist for stable obiee deployment

    - by user554629
    Common AIX configuration issues     ( last updated 27 Aug 2012 ) OBIEE is a complicated system with many moving parts and connection points.The purpose of this article is to provide a checklist to discuss OBIEE deployment with your systems administrators. The information in this article is time sensitive, and updated as I discover new  issues or details. What makes OBIEE different? When Tech Support suggests AIX component upgrades to a stable, locked-down production AIX environment, it is common to get "push back".  "Why is this necessary?  We aren't we seeing issues with other software?"It's a fair question that I have often struggled to answer; here are the talking points: OBIEE is memory intensive.  It is the entire purpose of the software to trade memory for repetitive, more expensive database requests across a network. OBIEE is implemented in C++ and is very dependent on the C++ runtime to behave correctly. OBIEE is aggressively thread efficient;  if atomic operations on a particular architecture do not work correctly, the software crashes. OBIEE dynamically loads third-party database client libraries directly into the nqsserver process.  If the library is not thread-safe, or corrupts process memory the OBIEE crash happens in an unrelated part of the code.  These are extremely difficult bugs to find. OBIEE software uses 99% common source across multiple platforms:  Windows, Linux, AIX, Solaris and HPUX.  If a crash happens on only one platform, we begin to suspect other factors.  load intensity, system differences, configuration choices, hardware failures.  It is rare to have a single product require so many diverse technical skills.   My role in support is to understand system configurations, performance issues, and crashes.   An analyst trained in Business Analytics can't be expected to know AIX internals in the depth required to make configuration choices.  Here are some guidelines. AIX C++ Runtime must be at  version 11.1.0.4$ lslpp -L | grep xlC.aixobiee software will crash if xlC.aix.rte is downlevel;  this is not a "try it" suggestion.Nov 2011 11.1.0.4 version  is appropriate for all AIX versions ( 5, 6, 7 )Download from here:https://www-304.ibm.com/support/docview.wss?uid=swg24031426 No reboot is necessary to install, it can even be installed while applications are using the current version.Restart the apps, and they will pick up the latest version. AIX 5.3 Technology Level 12 is required when running on Power5,6,7 processorsAIX 6.1 was introduced with the newer Power chips, and we have seen no issues with 6.1 or 7.1 versions.Customers with an unstable deployment, dozens of unexplained crashes, became stable after the upgrade.If your AIX system is 5.3, the minimum TL level should be at or higher than this:$ oslevel -s  5300-12-03-1107IBM typically supports only the two latest versions of AIX ( 6.1 and 7.1, for example).  AIX 5.3 is still supported and popular running in an LPAR. obiee userid limits$ ulimit -Ha  ( hard limits )$ ulimit -a   ( default limits )core file size (blocks)     unlimiteddata seg size (kbytes)      unlimitedfile size (blocks)          unlimitedmax memory size (kbytes)    unlimitedopen files                  10240 cpu time (seconds)          unlimitedvirtual memory (kbytes)     unlimitedIt is best to establish the values in /etc/security/limitsroot user is needed to observe and modify this file.If you modify a limit, you will need to relog in to change it again.  For example,$ ulimit -c 0$ ulimit -c 2097151cannot modify limit: Operation not permitted$ ulimit -c unlimited$ ulimit -c0There are only two meaningful values for ulimit -c ; zero or unlimited.Anything else is likely to produce a truncated core file that cannot be analyzed. Deploy 32-bit or 64-bit ?Early versions of OBIEE offered 32-bit or 64-bit choice to AIX customers.The 32-bit choice was needed if a database vendor did not supply a 64-bit client library.That's no longer an issue and beginning with OBIEE 11, 32-bit code is no longer shipped.A common error that leads to "out of memory" conditions to to accept the 32-bit memory configuration choices on 64-bit deployments.  The significant configuration choices are: Maximum process data (heap) size is in an AIX environment variableLDR_CNTRL=IGNOREUNLOAD@LOADPUBLIC@PREREAD_SHLIB@MAXDATA=0x... Two thread stack sizes are made in obiee NQSConfig.INI[ SERVER ]SERVER_THREAD_STACK_SIZE = 0;DB_GATEWAY_THREAD_STACK_SIZE = 0; Sort memory in NQSConfig.INI[ GENERAL ]SORT_MEMORY_SIZE = 4 MB ;SORT_BUFFER_INCREMENT_SIZE = 256 KB ; Choosing a value for MAXDATA:0x080000000  2GB Default maximum 32-bit heap size ( 8 with 7 zeros )0x100000000  4GB 64-bit breaking even with 32-bit ( 1 with 8 zeros )0x200000000  8GB 64-bit double 32-bit max0x400000000 16GB 64-bit safetyUsing 2GB heap size for a 64-bit process will almost certainly lead to an out-of-memory situation.Registers are twice as big ... consume twice as much memory in the heap.Upgrading to a 4GB heap for a 64-bit process is just "breaking even" with 32-bit.A 32-bit process is constrained by the 32-bit virtual addressing limits.  Heap memory is used for dynamic requirements of obiee software, thread stacks for each of the configured threads, and sometimes for shared libraries. 64-bit processes are not constrained in this way;  extra heap space can be configured for safety against a query that might create a sudden requirement for excessive storage.  If the storage is not available, this query might crash the whole server and disrupt existing users.There is no performance penalty on AIX for configuring more memory than required;  extra memory can be configured for safety.  If there are no other considerations, start with 8GB.Choosing a value for Thread Stack size:zero is the value documented to select an appropriate default for thread stack size.  My preference is to change this to an absolute value, even if you intend to use the documented default;  it provides better documentation and removes the "surprise" factor.There are two thread types that can be configured. GATEWAY is used by a thread pool to call a database client library to establish a DB connection.The default size is 256KB;  many customers raise this to 512KB ( no performance penalty for over-configuring ). This value must be set to 1 MB if Teradata connections are used. SERVER threads are used to run queries.  OBIEE uses recursive algorithms during the analysis of query structures which can consume significant thread stack storage.  It's difficult to provide guidance on a value that depends on data and complexity.  The general notion is to provide more space than you think you need,  "double down" and increase the value if you run out, otherwise inspect the query to understand why it is too complex for the thread stack.  There are protections built into the software to abort a single user query that is too complex, but the algorithms don't cover all situations.256 KB  The default 32-bit stack size.  Many customers increased this to 512KB on 32-bit.  A 64-bit server is very likely to crash with this value;  the stack contains mostly register values, which are twice as big.512 KB  The documented 64-bit default.  Some early releases of obiee didn't set this correctly, resulting in 256KB stacks.1 MB  The recommended 64-bit setting.  If your system only ever uses 512KB of stack space, there is no performance penalty for using 1MB stack size.2 MB  Many large customers use this value for safety.  No performance penalty.nqscheduler does not use the NQSConfig.INI file to set thread stack size.If this process crashes because the thread stack is too small, use this to set 2MB:export OBI_BACKGROUND_STACK_SIZE=2048 Shared libraries are not (shared) When application libraries are loaded at run-time, AIX makes a decision on whether to load the libraries in a "public" memory segment.  If the filesystem library permissions do not have the "Read-Other" permission bit, AIX loads the library into private process memory with two significant side-effects:* The libraries reduce the heap storage available.      Might be significant in 32-bit processes;  irrelevant in 64-bit processes.* Library code is loaded into multiple real pages for execution;  one copy for each process.Multiple execution images is a significant issue for both 32- and 64-bit processes.The "real memory pages" saved by using public memory segments is a minor concern.  Today's machines typically have plenty of real memory.The real problem with private copies of libraries is that they consume processor cache blocks, which are limited.   The same library instructions executing in different real pages will cause memory delays as the i-cache ( instruction cache 128KB blocks) are refreshed from real memory.   Performance loss because instructions are delayed is something that is difficult to measure without access to low-level cache fault data.   The machine just appears to be running slowly for no observable reason.This is an easy problem to detect, and an easy problem to correct.Detection:  "genld -l" AIX command produces a list of the libraries used by each process and the AIX memory address where they are loaded.32-bit public segment is 13 ( "dxxxxxxx" ).   private segments are 2-a.64-bit public segment is 9 ( "9xxxxxxxxxxxxxxx") ; private segment is 8.genld -l | grep -v ' d| 9' | sort +2provides a list of privately loaded libraries. Repair: chmod o+r <libname>AIX shared libraries will have a suffix of ".so" or ".a".Another technique is to change all libraries in a selected directory to repair those that might not be currently loaded.   The usual directories that need repair are obiee code, httpd code and plugins, database client libraries and java.chmod o+r /shr/dir/*.a /shr/dir/*.so Configure your system for diagnosticsProduction systems shouldn't crash, and yet bad things happen to good software.If obiee software crashes and produces a core, you should configure your system for reliable transfer of the failing conditions to Oracle Tech Support.  Here's what we need to be able to diagnose a core file from your system.* fullcore enabled. chdev -lsys0 -a fullcore=true* core naming enabled. chcore -n on -d* ulimit must not truncate core. see item 3.* pstack.sh is used to capture core documentation.* obidoc is used to capture current AIX configuration.* snapcore  AIX utility captures core and libraries. Use the proper syntax. $ snapcore -r corename executable-fullpath   /tmp/snapcore will contain the .pax.Z output file.  It is compressed.* If cores are directed to a common directory, ensure obiee userid can write to the directory.  ( chcore -p /cores -d ; chmod 777 /cores )The filesystem must have sufficient space to hold a crashing obiee application.Use:  df -k  Check the "Free" column ( not "% Used" )  8388608 is 8GB. Disable Oracle Client Library signal handlingThe Oracle DB Client Library is frequently distributed with the sqlplus development kit.By default, the library enables a signal handler, which will document a call stack if the application crashes.   The signal handler is not needed, and definitely disruptive to obiee diagnostics.   It needs to be disabled.   sqlnet.ora is typically located at:   $ORACLE_HOME/network/admin/sqlnet.oraAdd this line at the top of the file:   DIAG_SIGHANDLER_ENABLED=FALSE Disable async query in the RPD connection pool.This might be an obiee 10.1.3.4 issue only ( still checking  )."async query" must be disabled in the connection pools.It was designed to enable query cancellation to a database, and turned out to have too many edge conditions in normal communication that produced random corruption of data and crashes.  Please ensure it is turned off in the RPD. Check AIX error report (errpt).Errors external to obiee applications can trigger crashes.  $ /bin/errpt -aHardware errors ( firmware, adapters, disks ) should be reported to IBM support.All application core files are recorded by AIX;  the most recent ones are listed first. Reserved for something important to say.

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  • CodePlex Daily Summary for Tuesday, May 13, 2014

    CodePlex Daily Summary for Tuesday, May 13, 2014Popular ReleasesWinAudit: WinAudit Freeware v3.0: WinAudit.exe v3.0 MD5: 88750CCF49FF7418199B2645755830FA Known Issues: 1. Report creation can be very slow when right-to-left (Hebrew) characters are present. 2. Emsisoft Anti-Malware may stop and/or quarantine WinAudit. This happens when WinAudit attempts to obtain a list if running programmes. You will need to set an exception rule in Emsisoft to allow WinAudit to run.MVCwCMS - ASP.NET MVC CMS: MVCwCMS 2.2.2: Updated CKFinder config. For the installation instructions visit the documentation page: https://mvcwcms.codeplex.com/documentationTerraMap (Terraria World Map Viewer): TerraMap 1.0.4: Added support for the new Terraria v1.2.4 update. New items, walls, and tiles Fixed Issue 35206: Hightlight/Find doesn't work for Demon Altars Fixed finding Demon Hearts/Shadow Orbs Added ability to find Enchanted Swords (in the stone) and Water Bolt books Fixed installer not uninstalling older versions The setup file will make sure .NET 4 is installed, install TerraMap, create desktop and start menu shortcuts, add a .wld file association, and launch TerraMap. If you prefer the zip ...WPF Localization Extension: v2.2.1: Issue #9277 Issue #9292 Issue #9311 Issue #9312 Issue #9313 Issue #9314CtrlAltStudio Viewer: CtrlAltStudio Viewer 1.2.1.41167 Release: This release of the CtrlAltStudio Viewer includes the following significant features: Oculus Rift support. Stereoscopic 3D display support. Variable walking / flying speed. Xbox 360 Controller support. Kinect for Windows support. Based on Firestorm viewer 4.6.5 codebase. For more details, see the release notes linked to below. Release notes: http://ctrlaltstudio.com/viewer/release-notes/1-2-1-41167-release Support info: http://ctrlaltstudio.com/viewer/support Privacy policy: http:/...ExtJS based ASP.NET Controls: FineUI v4.0.6: FineUI(???) ?? ExtJS ??? ASP.NET ??? FineUI??? ?? No JavaScript,No CSS,No UpdatePanel,No ViewState,No WebServices ??????? ?????? IE 8.0+、Chrome、Firefox、Opera、Safari ???? Apache License v2.0 ?:ExtJS ?? GPL v3 ?????(http://www.sencha.com/license) ???? ??:http://fineui.com/ ??:http://fineui.com/bbs/ ??:http://fineui.com/demo/ ??:http://fineui.com/doc/ ??:http://fineui.codeplex.com/ FineUI ???? ExtJS ????????,???? ExtJS ?,?????: 1. ????? FineUI ? ExtJS ? http://fineui.com/bbs/forum.ph...Office App Model Samples: Office App Model Samples v2.0: Office App Model Samples v2.0GMare: GMare Beta 1.1: Features Added: Overhauled interface Re-wrote most controls and forms Automatic room creation on application open Room properties bar to change various room properties Now able to use a background from a supported Game Maker project file Block instances implemented More instance editing features like multi-Select, cherry pick select, replace, and set position More instance options on the instance list Flexible XML based .gmpx human readable project file format Game...Readable Passphrase Generator: KeePass Plugin 0.13.0: Version 0.13.0 Added "mutators" which add uppercase and numbers to passphrases (to help complying with upper, lower, number complexity rules). Additional API methods which help consuming the generator from 3rd party c# projects. 13,160 words in the default dictionary (~600 more than previous release).CS-Script for Notepad++ (C# intellisense and code execution): Release v1.0.25.0: Release v1.0.25.0 MemberInfo/MethodInfo popup is now positioned properly to fit the screen In MethodInfo popup method signatures are word-wrapped Implemented Debug text value visualizer Pining sub-values from Watch PanelxFunc: xFunc 2.15.3: Added #53R.NET: R.NET 1.5.12: R.NET 1.5.12 is a beta release towards R.NET 1.6. You are encouraged to use 1.5.12 now and give feedback. See the documentation for setup and usage instructions. Main changes for R.NET 1.5.12: The C stack limit was not disabled on Windows. For reasons possibly peculiar to R, this means that non-concurrent access to R from multiple threads was not stable. This is now fixed, with the fix validated with a unit test. Thanks to Odugen, skyguy94, and previously others (evolvedmicrobe, tomasp) fo...CTI Text Encryption: CTI Text Encryption 5.2: Change log: 5.2 - Remove Cut button. - Fixed Reset All button does not reset encrypted text column. - Switch button location between Copy and Paste. - Enable users to use local fonts to display characters of their language correctly. (A font settings file will be saved at the same folder of this program.) 5.1 - Improve encryption process. - Minor UI update. - Version 5.1 is not compatible with older version. 5.0 - Improve encryption algorithm. - Simply inner non-encryption related mec...SEToolbox: SEToolbox 01.029.006 Release 1: Fix to allow keyboard search on load dialog. (type the first few letters of your save) Fixed check for new release. Changed the way ship details are loaded to alleviate load time for worlds with very large ships (100,000+ blocks). Fixed Image importer, was incorrectly listing 'Asteroid' as import option. Minor changes to menus (text and appearance) for clarity and OS consistency. Added in reading of world palette for color dialog editor. WIP on subsystem editor. Can now multiselec...Media Companion: Media Companion MC3.597b: Thank you for being patient, againThere are a number of fixes in place with this release. and some new features added. Most are self explanatory, so check out the options in Preferences. Couple of new Features:* Movie - Allow save Title and Sort Title in Title Case format. * Movie - Allow save fanart.jpg if movie in folder. * TV - display episode source. Get episode source from episode filename. Fixed:* Movie - Added Fill Tags from plot keywords to Batch Rescraper. * Movie - Fixed TMDB s...SimCityPak: SimCityPak 0.3.0.0: Contains several bugfixes, newly identified properties and some UI improvements. Main new features UI overhaul for the main index list: Icons for each different index, including icons for different property files Tooltips for all relevant fields Removed clutter Identified hundreds of additional properties (thanks to MaxisGuillaume) - this should make modding gameplay easierMagick.NET: Magick.NET 6.8.9.002: Magick.NET linked with ImageMagick 6.8.9.0.VidCoder: 1.5.22 Beta: Added ability to burn SRT subtitles. Updated to HandBrake SVN 6169. Added checks to prevent VidCoder from running with a database version newer than it expects. Tooltips in the Advanced Video panel now trigger on the field labels as well as the fields themselves. Fixed updating preset/profile/tune/level settings on changing video encoder. This should resolve some problems with QSV encoding. Fixed tunes and profiles getting set to blank when switching between x264 and x265. Fixed co...Tiny Deduplicator: Tiny Deduplicator 1.0.0.1: Project Description Tiny Deduplicator is a file deduplicator which can scan for duplicate files, and allows the user to control which duplicates they are going to keep, and which are going to be recycled. Tiny Deduplicator will never delete files directly-- rather, it sends them to the recycle bin for you to confirm the deletion of. In its current form, Tiny Deduplicator is a mere 23KB (including the GUI); however, it has the following features: Easily browse and select which directory to ...NuGet: NuGet 2.8.2: We will be releasing a 2.8.2 version of our own NuGet packages and the NuGet.exe command-line tool. The 2.8.2 release will not include updated VS or WebMatrix extensions. NuGet.Server.Extensions.dll needs to be used alongside NuGet-Signed.exe to provide the NuGet.exe mirror functionality.New Projects2112110004: bùi th? bé di?m2112110007: l?p trình hu?ng d?i tu?ng (OOP) Ph?m H?u Dung2112110019: Nguy?n Duy Hòa_2112110019 CCQ1211A2112110032: Truong Ha Mi2112110041: nguyen manh thuong quan2112110079: VU TH? MAI ANH - L?P TRÌNH HU?NG Ð?I TU?NG(OOP) - L?P CCQ1211B - MSSV 2112110079Adapter Pattern: Super duper simple project that explains how the Adapter Design Pattern works.Aspose for Sitefinity: Aspose Sitefinity Content Export Add-on allow users to export online content into Microsoft Word or Adobe Acrobat PDF document using Aspose.Words.baitapHDT: le ba thuan thanhCaltech Software: Caltech SoftwareDCM Ventas: DCMEntityBinder: Entity Binder is a C# library to help you to read data from xml or json file and bind them directly to data object.FATCAClient: A simple application for populating and viewing XML files which comply with the published FATCA schema.Grade Calculator For BTEC First Diploma in IT level 2: Grade Calculator For BTEC First Diploma in IT level 2HMS_TEST: ????? ???? ??????.lock Keywords Demo: ?? lock ????????,????? this、string、typeof(MyType) ?????mbtPdfAsm: command line pdf file assembler/merger.Orchard CMS Syndication: Implementation of a module that provides OData protocol and then enables third parties to query (custom) creatable content types embedded in an Orchard CMS SitePerfAnalyzer: TemporaryPluralSight Downloader: This project allow to Download PluralSight (PluralSight downloader) video tutorials even with free account and many more features. Use at your own risk.ProView: Image viewer and data entry application for renaming image files.Real Estate website Clark: Real Estate website ClarkSE Community Modding API: This project aims to simplify the modding process of Space Engineers® game from Keen Software HouseSirGorn robi PeHaPa: Projekt na prace zespolowa.TPC1 Grupo14: TPC1Grupo14TypeScriptSheet (Spreadsheet webapp create using TypeScript): TypeScriptSheet. This project is Spread sheet Web Application. It is medium featured spread sheet built using TypeScript and JQuery.VB Converter: Convert your VB6 code to .NET (C# and VB .NET) with this tool.Web Site For Instagram: This is a web app for Instagram using asp.net MVC.WorkProject: This is WorkProject.Z Entity Framework Extensions: ab??????-??????【??】??????????: ??????,?????????,?????????????。?????????????,?????????,???????。 ??????-??????【??】??????????: ??????????????????????????,???????????????,????????????????! ??????-??????【??】??????????: ??????????????????,???????、????、????、??????、???????,??????,???????????。 ????-????【??】????????: ??????????????,???????、???????????,????????,????,?????????,??????,??????! ????-????【??】????????: ???????????????"????,????"???,????????????????????????,??????????????。 ??????-??????【??】??????????: ????????????,????,??????????? ???? ???? ?????????,???,??,?????! ??????-??????【??】??????????: ???????????? ???? ???? ???? ???? ???? ??????? ?????,????????????????. ????-????【??】????????: ??????????????、????、????、??????、????、????????,????????、?????????,?????。 ?????-?????【??】?????????: ??????????????????????????,???????????????????????,???????。 ?????-?????【??】?????????: ??????????????:?????? ???? ??????,???????,??????,???????。 ??????-??????【??】??????????: ?????????????????,???????????????。?????????????,???????,?????????。 ??????-??????【??】??????????: ????????????????????,?????????????,???????????.????????????,????????????! ????-????【??】????????: ????????????:????,????,????,???????,????????,??????:????????,?????! ?????-?????【??】?????????: ?????????????????,??:??????,????,????,????,?????,??????????????. ?????-?????【??】?????????: ??????,??,????????。 ... ??????????????????、??????????????????... ??????-??????【??】??????????: ?????????????????,??????????????、???????、???????、???????、?????! ??????-??????【??】??????????: ?????????????????,?????????????。????????????,???????,???????,?????,?????。 ??????-??????【??】??????????: ??????????????????????????,???????????,????????,?????????????????????。 ????-????【??】????????: ??????????????????????,????,????,??????????。???????????????,??,??,??????????,??????... ??????-??????【??】??????????: ??????????????、?????????,?????????,????,????????,????????????????! ????-????【??】????????: ??????????????????????,?????????,??????????,????????,?????! ??????-??????【??】??????????: ???????????????、????、????、??????、????、???????,?????,?????????! ??????-??????【??】??????????: ????????????????????????、??????,????、?????、????, ?????????,?????????????! ????-????【??】????????: ????????????????、????、??????、????????,????????????,???????????! ?????-?????【??】?????????: ????????????????????、????、????、??????、???????,??????、??????。 ?????-?????【??】?????????: ???????,??????,?????????????????????,???????????????????????。 ??????-??????【??】??????????: ????????????????????,?????????????????????,?????,????,???????. ??????-??????【??】??????????: ??????????????、??????、????、?????、?????!????,????????????????!????。 ????-????【??】????????: ??????????????????,?????,???????,???????????,??????! ?????-?????【??】?????????: ???????????、??、???????????,??????,????????,??????????????????...????。 ?????-?????【??】?????????: ??????????????、???????,?????????,???????????????,?????????????。

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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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  • 12c - flashforward, flashback or see it as of now...

    - by noreply(at)blogger.com (Thomas Kyte)
    Oracle 9i exposed flashback query to developers for the first time.  The ability to flashback query dates back to version 4 however (it just wasn't exposed).  Every time you run a query in Oracle it is in fact a flashback query - it is what multi-versioning is all about.However, there was never a flashforward query (well, ok, the workspace manager has this capability - but with lots of extra baggage).  We've never been able to ask a table "what will you look like tomorrow" - but now we do.The capability is called Temporal Validity.  If you have a table with data that is effective dated - has a "start date" and "end date" column in it - we can now query it using flashback query like syntax.  The twist is - the date we "flashback" to can be in the future.  It works by rewriting the query to transparently the necessary where clause and filter out the right rows for the right period of time - and since you can have records whose start date is in the future - you can query a table and see what it would look like at some future time.Here is a quick example, we'll start with a table:ops$tkyte%ORA12CR1> create table addresses  2  ( empno       number,  3    addr_data   varchar2(30),  4    start_date  date,  5    end_date    date,  6    period for valid(start_date,end_date)  7  )  8  /Table created.the new bit is on line 6 (it can be altered into an existing table - so any table  you have with a start/end date column will be a candidate).  The keyword is PERIOD, valid is an identifier I chose - it could have been foobar, valid just sounds nice in the query later.  You identify the columns in your table - or we can create them for you if they don't exist.  Then you just create some data:ops$tkyte%ORA12CR1> insert into addresses (empno, addr_data, start_date, end_date )  2  values ( 1234, '123 Main Street', trunc(sysdate-5), trunc(sysdate-2) );1 row created.ops$tkyte%ORA12CR1>ops$tkyte%ORA12CR1> insert into addresses (empno, addr_data, start_date, end_date )  2  values ( 1234, '456 Fleet Street', trunc(sysdate-1), trunc(sysdate+1) );1 row created.ops$tkyte%ORA12CR1>ops$tkyte%ORA12CR1> insert into addresses (empno, addr_data, start_date, end_date )  2  values ( 1234, '789 1st Ave', trunc(sysdate+2), null );1 row created.and you can either see all of the data:ops$tkyte%ORA12CR1> select * from addresses;     EMPNO ADDR_DATA                      START_DAT END_DATE---------- ------------------------------ --------- ---------      1234 123 Main Street                27-JUN-13 30-JUN-13      1234 456 Fleet Street               01-JUL-13 03-JUL-13      1234 789 1st Ave                    04-JUL-13or query "as of" some point in time - as  you can see in the predicate section - it is just doing a query rewrite to automate the "where" filters:ops$tkyte%ORA12CR1> select * from addresses as of period for valid sysdate-3;     EMPNO ADDR_DATA                      START_DAT END_DATE---------- ------------------------------ --------- ---------      1234 123 Main Street                27-JUN-13 30-JUN-13ops$tkyte%ORA12CR1> @planops$tkyte%ORA12CR1> select * from table(dbms_xplan.display_cursor);PLAN_TABLE_OUTPUT-------------------------------------------------------------------------------SQL_ID  cthtvvm0dxvva, child number 0-------------------------------------select * from addresses as of period for valid sysdate-3Plan hash value: 3184888728-------------------------------------------------------------------------------| Id  | Operation         | Name      | Rows  | Bytes | Cost (%CPU)| Time     |-------------------------------------------------------------------------------|   0 | SELECT STATEMENT  |           |       |       |     3 (100)|          ||*  1 |  TABLE ACCESS FULL| ADDRESSES |     1 |    48 |     3   (0)| 00:00:01 |-------------------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------   1 - filter((("T"."START_DATE" IS NULL OR              "T"."START_DATE"<=SYSDATE@!-3) AND ("T"."END_DATE" IS NULL OR              "T"."END_DATE">SYSDATE@!-3)))Note-----   - dynamic statistics used: dynamic sampling (level=2)24 rows selected.ops$tkyte%ORA12CR1> select * from addresses as of period for valid sysdate;     EMPNO ADDR_DATA                      START_DAT END_DATE---------- ------------------------------ --------- ---------      1234 456 Fleet Street               01-JUL-13 03-JUL-13ops$tkyte%ORA12CR1> @planops$tkyte%ORA12CR1> select * from table(dbms_xplan.display_cursor);PLAN_TABLE_OUTPUT-------------------------------------------------------------------------------SQL_ID  26ubyhw9hgk7z, child number 0-------------------------------------select * from addresses as of period for valid sysdatePlan hash value: 3184888728-------------------------------------------------------------------------------| Id  | Operation         | Name      | Rows  | Bytes | Cost (%CPU)| Time     |-------------------------------------------------------------------------------|   0 | SELECT STATEMENT  |           |       |       |     3 (100)|          ||*  1 |  TABLE ACCESS FULL| ADDRESSES |     1 |    48 |     3   (0)| 00:00:01 |-------------------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------   1 - filter((("T"."START_DATE" IS NULL OR              "T"."START_DATE"<=SYSDATE@!) AND ("T"."END_DATE" IS NULL OR              "T"."END_DATE">SYSDATE@!)))Note-----   - dynamic statistics used: dynamic sampling (level=2)24 rows selected.ops$tkyte%ORA12CR1> select * from addresses as of period for valid sysdate+3;     EMPNO ADDR_DATA                      START_DAT END_DATE---------- ------------------------------ --------- ---------      1234 789 1st Ave                    04-JUL-13ops$tkyte%ORA12CR1> @planops$tkyte%ORA12CR1> select * from table(dbms_xplan.display_cursor);PLAN_TABLE_OUTPUT-------------------------------------------------------------------------------SQL_ID  36bq7shnhc888, child number 0-------------------------------------select * from addresses as of period for valid sysdate+3Plan hash value: 3184888728-------------------------------------------------------------------------------| Id  | Operation         | Name      | Rows  | Bytes | Cost (%CPU)| Time     |-------------------------------------------------------------------------------|   0 | SELECT STATEMENT  |           |       |       |     3 (100)|          ||*  1 |  TABLE ACCESS FULL| ADDRESSES |     1 |    48 |     3   (0)| 00:00:01 |-------------------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------   1 - filter((("T"."START_DATE" IS NULL OR              "T"."START_DATE"<=SYSDATE@!+3) AND ("T"."END_DATE" IS NULL OR              "T"."END_DATE">SYSDATE@!+3)))Note-----   - dynamic statistics used: dynamic sampling (level=2)24 rows selected.All in all a nice, easy way to query effective dated information as of a point in time without a complex where clause.  You need to maintain the data - it isn't that a delete will turn into an update the end dates a record or anything - but if you have tables with start/end dates, this will make it much easier to query them.

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  • StackOverflow in Silverlight 4

    - by AlishahNovin
    I just upgraded my Silverlight 3 project to Silverlight 4. After spending 2 hours fixing up all the code issues, I'm now able to build my project... and low and behold, every single browser I attempt to run in is crashing, and I'm getting the following exception in code: An unhandled exception of type 'System.StackOverflowException' occurred in System.Windows.dll Hopefully StackOverflow can help me with this... StackOverflow. Has anyone else seen this?

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  • How to do long polling from iPhone application?

    - by Hitesh Manchanda
    I want to create a iPhone chat application and i do not have any experience of socket programming so can u please help me understand How can i do long polling from iPhone application? Also can NSURLConnection be used for this purpose or we need to use some low level API? Are there any libraries available for the same?

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  • GDI handles in a DotNET application

    - by David Rutten
    My pure DotNET library runs as a plugin inside an unmanaged desktop application. I've been getting a steady (though low) stream of crash reports that seem to indicate a problem with GDI handles (fonts in error messages etc. revert to the system font, display of all sorts of controls break down, massive crash shortly after). My Forms have few controls, but I do a lot of GDI+ drawing in User controls. What's a good way to tell how many handles I'm using, or even leaking? Thanks, David

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  • Why is Html.DropDownList() producing <select name="original_name.name"> instead of just <select name

    - by DanM
    I have an editor template whose job is to take a SelectList as its model and build a select element in html using the Html.DropDownList() helper extension. I'm trying to assign the name attribute for the select based on a ModelMetadata property. (Reason: on post-back, I need to bind to an object that has a different property name for this item than the ViewModel used to populate the form.) The problem I'm running into is that DropDownList() is appending the name I'm providing instead of replacing it, so I end up with names like categories.category instead of category. Here is some code for you to look at... SelectList.ascx <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<System.Web.Mvc.SelectList>" %> <%= Html.DropDownList( (string)ViewData.ModelMetadata.AdditionalValues["PropertyName"], Model) %> Resulting HTML <select id="SkillLevels_SkillLevel" name="SkillLevels.SkillLevel"> <option value="1">High</option> <option value="2">Med</option> <option selected="selected" value="3">Low</option> </select> Expected HTML <select id="SkillLevels_SkillLevel" name="SkillLevel"> <option value="1">High</option> <option value="2">Med</option> <option selected="selected" value="3">Low</option> </select> Also tried <%= Html.Encode((string)ViewData.ModelMetadata.AdditionalValues["PropertyName"])%> ...which resulted in "SkillLevel" (not "SkillLevels.SkillLevel"), proving that the data stored in metadata is correct. and <%= Html.DropDownList( (string)ViewData.ModelMetadata.AdditionalValues["PropertyName"], Model, new { name = (string)ViewData.ModelMetadata.AdditionalValues["PropertyName"] }) %> ...which still resulted in <select name=SkillLevels.Skilllevel>. Questions What's going on here? Why does it append the name instead of just using it? Can you suggest a good workaround? Update: I ended up writing a helper extension that literally does a find/replace on the html text: public static MvcHtmlString BindableDropDownListForModel(this HtmlHelper helper) { var propertyName = (string)helper.ViewData.ModelMetadata.AdditionalValues["PropertyName"]; var compositeName = helper.ViewData.ModelMetadata.PropertyName + "." + propertyName; var rawHtml = helper.DropDownList(propertyName, (SelectList)helper.ViewData.Model); var bindableHtml = rawHtml.ToString().Replace(compositeName, propertyName); return MvcHtmlString.Create(bindableHtml); }

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  • Void pointers in C

    - by avd
    I have written this qsort: void qsort(void *a[],int low,int high, int (*compare)(void*,void*)); When I call this on char *strarr[5]; It says invalid conversion from char** to void**. Why this is wrong? This is the code:http://codepad.org/Flfm2zAE

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  • Creating a secure SQL Server 2008 database environment

    - by user279521
    I am in the process of setting up a corporate SQL Server 2008 database. The data on this machine will be related to financial services. There will be low level traffic (not like your average investment broker's website). However, a secure data environment is very crucial. What would I need to know / do in order to ensure that I have a secure database?

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  • Matlab - binary vector with high concentration of 1s (or 0s)

    - by JohnIdol
    What's the best way to generate a number X of random binary vectors of size N with concentration of 1s (or, simmetrically, of 0s) that spans from very low to very high? Using randint or unidrnd (as in this question) will generate binary vectors with uniform distributions, which is not what I need in this case. Any help appreciated!

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  • Short Python alphanumeric hash with minimal collisions

    - by ensnare
    I'd like to set non-integer primary keys for a table using some kind of hash function. md5() seems to be kind of long (32-characters). What are some alternative hash functions that perhaps use every letter in the alphabet as well as integers that are perhaps shorter in string length and have low collision rates? Thanks!

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  • C# Confusing Results from Performance Test

    - by aip.cd.aish
    I am currently working on an image processing application. The application captures images from a webcam and then does some processing on it. The app needs to be real time responsive (ideally < 50ms to process each request). I have been doing some timing tests on the code I have and I found something very interesting (see below). clearLog(); log("Log cleared"); camera.QueryFrame(); camera.QueryFrame(); log("Camera buffer cleared"); Sensor s = t.val; log("Sx: " + S.X + " Sy: " + S.Y); Image<Bgr, Byte> cameraImage = camera.QueryFrame(); log("Camera output acuired for processing"); Each time the log is called the time since the beginning of the processing is displayed. Here is my log output: [3 ms]Log cleared [41 ms]Camera buffer cleared [41 ms]Sx: 589 Sy: 414 [112 ms]Camera output acuired for processing The timings are computed using a StopWatch from System.Diagonostics. QUESTION 1 I find this slightly interesting, since when the same method is called twice it executes in ~40ms and when it is called once the next time it took longer (~70ms). Assigning the value can't really be taking that long right? QUESTION 2 Also the timing for each step recorded above varies from time to time. The values for some steps are sometimes as low as 0ms and sometimes as high as 100ms. Though most of the numbers seem to be relatively consistent. I guess this may be because the CPU was used by some other process in the mean time? (If this is for some other reason, please let me know) Is there some way to ensure that when this function runs, it gets the highest priority? So that the speed test results will be consistently low (in terms of time). EDIT I change the code to remove the two blank query frames from above, so the code is now: clearLog(); log("Log cleared"); Sensor s = t.val; log("Sx: " + S.X + " Sy: " + S.Y); Image<Bgr, Byte> cameraImage = camera.QueryFrame(); log("Camera output acuired for processing"); The timing results are now: [2 ms]Log cleared [3 ms]Sx: 589 Sy: 414 [5 ms]Camera output acuired for processing The next steps now take longer (sometimes, the next step jumps to after 20-30ms, while the next step was previously almost instantaneous). I am guessing this is due to the CPU scheduling. Is there someway I can ensure the CPU does not get scheduled to do something else while it is running through this code?

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  • C++ OpenSource project for beginner programmer?

    - by VeminZ
    I`m a beginner C++ programmer. And I want to pursue my career in system- and driver-programming. Can you suggest me an opensource projects to I improve my skills in low-level development? I am looking for a project with the following characteristic: - on C\C++ language based - a small project with a small amount of code, yet - UNIX-based systems designed Do you know that something like this?

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  • Ndepend CQL to find methods of certain types using particular framework assembly

    - by icelava
    In order to check if types not derived from certain base classes are using a low-level framework assembly, the following query can be used. SELECT TYPES WHERE IsDirectlyUsing "ASSEMBLY:Framework.Data" AND !(DeriveFrom "App.BaseTypes.BusinessFacadeBase" OR DeriveFrom "App.BaseTypes.BusinessComponentBase" OR DeriveFrom "App.BaseTypes.DataAccessComponentBase") Now I wish to drill down further to see which methods from those classes are actually doing so. But the thing is if I change the query target from TYPES to METHODS then DeriveFrom is not going to apply. How can these criteria be preserved?

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  • Any sample C# project that highlights separate data access layer (using EF) to business logic layer

    - by Greg
    Hi, I'm interested in having a look at a small sample project that would highlight a good technique to separate data access layer (using Entity Framework) to business logic layer. In C# would be good. That is, it would highlight how to pass data between the layer without coupling them. That is, the assumption here is not to use the EF classes in the Business Logic layer, and how to achieve this low coupling, but minimizing plumbing code.

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  • How can two eclipse plugin use the same preferences store?

    - by St.Shadow
    I have two plugins, say com.site.plugin.core and com.site.plugin.ui. I'd like to separate core part from UI part, so at plugin com.site.plugin.ui I created Preferences page where I defined some preferences, which should be used by com.site.plugin.core. I check article at Eclipse site, but it is quite outdated, and linked bug also do not provide much info. So is it possible to do this using standard Eclipse mechanism, or I need use direct low-level API via package org.eclipse.core.runtime.preferences?

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  • Object database for website

    - by Damian
    I was planning to use db4o for a website. It's a microblog site with small posts and comments developed in java. The thing is I contacted db4o support asking if db4o would be suitable for a website, and they answered me that only for websites with low concurrency. That means with few requests? So, now I think db4o will not be a good choice. Do you know if there is any object database for java suitable for a website?

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  • Is One Tool or a Suite of Tools Better for Scrum?

    - by Rob Wells
    G'day, Edit: We've been using Scrum very successfully for several years on several projects of varying sizes. In fact, our team developed the successful iPlayer project for the BBC using a classical Scrum approach. After using various combinations of tools, some high-tech, some low-tech, across these projects we now wish to try adopting a suitable tool suite. Our manager is to some extent attempting to force the adoption of a single suite of tools for Scrum. I've looked at the SO question "Best Scrum tools" and most people seem to recommend either: a suite of low-tech solutions, e.g. whiteboards, post-its, index cards, etc., or a monolithic tool that tries to satisfy as much as possible of the process, e.g. Agilo, Mingle, ScrumWorks, Target Process, etc. Our team is currently evaluating several different Scrum tools. However, we are looking at selecting a single, monolithic tool, e.g. Agilo. All of the "one-stop" solutions have their strengths and weaknesses with the serious enterprise type solutions being the best sort of fit. But all have some short comings. After reading the paper "Peer Code Review: An Agile Process" over at SmartBear I started wondering if we were trying to force adoption of a tool on a "best fit" basis. I think you can take a couple of reference artefacts of the Scrum development process, say user stories, epics and themes, and the code base which must use a well-known SCM, e.g. SVN, Hg, etc. Then if we take that as the common reference points for the tools employed then we would be able to use a group of tools to handle the different aspects of the Scrum process rather than try forcing a fit of a single tool would is a bit like forcing a square peg into the round hole. In this way, providing you've agreed your common reference points, you can use several tools, each performing their role better than a could be done by a single component in a monolithic tool suite. Is this a more sensible approach? Are the two reference points I mentioned above suitable, or is their a better choice of points where the tools would meet? cheers,

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