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• CodePlex Daily Summary for Tuesday, October 23, 2012

  CodePlex Daily Summary for Tuesday, October 23, 2012Popular ReleasesDNN Module Creator: 01.01.00: Updated templates for DNN7 ( ie. DAL2, Web Service API ). Numerous bug fixes and enhancements.WPF Application Framework (WAF): WPF Application Framework (WAF) 2.5.0.390: Version 2.5.0.390 (Release Candidate): This release contains the source code of the WPF Application Framework (WAF) and the sample applications. Requirements .NET Framework 4.0 (The package contains a solution file for Visual Studio 2010) The unit test projects require Visual Studio 2010 Professional Changelog Legend: [B] Breaking change; [O] Marked member as obsolete WAF: Fix recent file list remove issue. WAF: Minor code improvements. BookLibrary: Fix Blend design time support o...ltxml.js - LINQ to XML for JavaScript: 1.0 - Beta 1: First release!EvoGame: EvoGame PreAlpha v0.0.2_c InDev: Yup, a new update, go the sprites working.Ficharts.Net: 1.0 Alpha: ??Ficharts????、???????????，?? ??/???、??/???、???、??/???ZXMAK2: Version 2.6.6.0: + fix refresh debugger after open RZX file + add NoFlic video filterSQLLib: Alpha release 17: Added CLR UDFs: * clr.fn_regex_instr - similar to Oracle REGEX_INSTR * clr.fn_regex_substr - similar to Oracle REGEX_SUBSTR To deploy CLR objects copy ClrAgg.dll and ClrRegEx.dll to a folder of you choice (currently deployment script points to C:\Program Files\Microsoft SQL Server\100\CLR\ClrAgg.dll) and execute deployment scripts InstallCLRAggregates.sql and InstallCLRRegEx.sql Thank you for rating the download and/or your feedback.EPiServer CMS ElencySolutions.MultipleProperty: ElencySolutions.MultipleProperty v1.6.3: The ElencySolutions.MulitpleProperty property controls have been developed by Lee Crowe a technical developer at Fortune Cookie (London). Installation notes The property copy page can be locked down by adding the following location element, the path of this will be different depending on whether you use the embedded or non embedded resource version. When installing the nuget package these will be added automatically, examples below: Embedded: <location path="util/ElencySolutionsMultipleP...Fiskalizacija za developere: FiskalizacijaDev 1.1: Ovo je prva nadogradnja ovog projekta nakon inicijalnog predstavljanja - dodali smo nekoliko feature-a, bilo zato što smo sami primijetili da bi ih bilo dobro dodati, bilo na osnovu vaših sugestija - hvala svima koji su se ukljucili :) Ovo su stvari riješene u v1.1.: 1. Bilo bi dobro da se XML dokument koji se šalje u CIS može snimiti u datoteku (http://fiskalizacija.codeplex.com/workitem/612) 2. Podrška za COM DLL (VB6) (http://fiskalizacija.codeplex.com/workitem/613) 3. Podrška za DOS (unu...MCEBuddy 2.x: MCEBuddy 2.3.4: Changelog for 2.3.4 (32bit and 64bit) 1. Fixed a bug introduced in 2.3.3 that would cause HD recordings and recordings with multiple audio channels to fail. 2. Updated <encoder-unsupported> option to compare with all Audio tracks for videos with multiple audio tracks. 3. Fixed a bug with SRT and EDL files, when input and output directory are the same the files are not preserved.BlogEngine.NET: BlogEngine.NET 2.7 RC: Cheap ASP.NET Hosting - $4.95/Month - Click Here!! Click Here for More Info Cheap ASP.NET Hosting - $4.95/Month - Click Here! dot This is a Release Candidate version for BlogEngine.NET 2.7. The most current, stable version of BlogEngine.NET is version 2.6. Find out more about the BlogEngine.NET 2.7 RC here. To get started, be sure to check out our installation documentation. If you are upgrading from a previous version, please take a look at the Upgrading to BlogEngine.NET 2.7 instructions...Pulse: Pulse 0.6.3.0: Fixed a number of bugs that showed up since my update yesterday. Fixes included are for: - Weird issue where the initial "Nature" wallbase.cc search would duplicate itself - After changing a providers settings it wouldn't take affect until you restarted Pulse (removing or adding a provider entirely did take effect though) - Another small issue with the regex for the wallbase.cc wallpapers that I tweaked yesterday, seems good now though.Liberty: v3.4.0.0 Release 20th October 2012: Change Log -Added -Halo 4 support (invincibility, ammo editing) -Reach A warning dialog now shows up when you first attempt to swap a weapon -Fixed -A few minor bugsClosedXML - The easy way to OpenXML: ClosedXML 0.68.1: ClosedXML now resolves formulas! Yes it finally happened. If you call cell.Value and it has a formula the library will try to evaluate the formula and give you the result. For example: var wb = new XLWorkbook(); var ws = wb.AddWorksheet("Sheet1"); ws.Cell("A1").SetValue(1).CellBelow().SetValue(1); ws.Cell("B1").SetValue(1).CellBelow().SetValue(1); ws.Cell("C1").FormulaA1 = "\"The total value is: \" & SUM(A1:B2)"; var...Orchard Project: Orchard 1.6 RC: RELEASE NOTES This is the Release Candidate version of Orchard 1.6. You should use this version to prepare your current developments to the upcoming final release, and report problems. Please read our release notes for Orchard 1.6 RC: http://docs.orchardproject.net/Documentation/Orchard-1-6-Release-Notes Please do not post questions as reviews. Questions should be posted in the Discussions tab, where they will usually get promptly responded to. If you post a question as a review, you wil...Rawr: Rawr 5.0.1: This is the Downloadable WPF version of Rawr!For web-based version see http://elitistjerks.com/rawr.php You can find the version notes at: http://rawr.codeplex.com/wikipage?title=VersionNotes Rawr Addon (NOT UPDATED YET FOR MOP)We now have a Rawr Official Addon for in-game exporting and importing of character data hosted on Curse. The Addon does not perform calculations like Rawr, it simply shows your exported Rawr data in wow tooltips and lets you export your character to Rawr (including ba...Yahoo! UI Library: YUI Compressor for .Net: Version 2.1.1.0 - Sartha (BugFix): - Revered back the embedding of the 2x assemblies.Visual Studio Team Foundation Server Branching and Merging Guide: v2.1 - Visual Studio 2012: Welcome to the Branching and Merging Guide What is new? The Version Control specific discussions have been moved from the Branching and Merging Guide to the new Advanced Version Control Guide. The Branching and Merging Guide and the Advanced Version Control Guide have been ported to the new document style. See http://blogs.msdn.com/b/willy-peter_schaub/archive/2012/10/17/alm-rangers-raising-the-quality-bar-for-documentation-part-2.aspx for more information. Quality-Bar Details Documentatio...D3 Loot Tracker: 1.5.5: Compatible with 1.05.Write Once, Play Everywhere: MonoGame 3.0 (BETA): This is a beta release of the up coming MonoGame 3.0. It contains an Installer which will install a binary release of MonoGame on windows boxes with the following platforms. Windows, Linux, Android and Windows 8. If you need to build for iOS or Mac you will need to get the source code at this time as the installers for those platforms are not available yet. The installer will also install a bunch of Project templates for Visual Studio 2010 , 2012 and MonoDevleop. For those of you wish...New ProjectsAddition of two numbers: Addition of two integer numbersAddTwoNumbers: Add two numbersASP_BANMAYTINH: Xây d?ng web bán máy tính b?ng ASPAvalon MVC: Do not use, still in alphaCaio Proiete's HG Playground: Simple test project to leverage Mercurial features using CodePlexCaio Proiete's TFS Playground: Simple test project to leverage TFS features using CodePlexcodeplexaddproject: Task 1 adding two numbers.Compresor markov orden 1 shannon: Compresor de fuentes basado en el algoritmo de shannon con markov orden 1Cricket Mania: addd39 grid system: A web-based combat grid system for use in play-by-post DnD (or similar) role playing games.DarkSky Tagit: An Orchard module that exposes the jQuery Tagit plugin written by Hailwood as a script resource.DnnExpert: ??? ????? ?? ???? ???? ????? ? ???? ??? ?????? ??? ?? ???? ?? ???? ?? ???????? ???? ?? ???? ??? ???? ?? ?? ? ?????? ????? ???? ? ?????? ? ???? ???? ?? ????.Expandable Text/HTML for DotNetNuke by IowaComputerGurus Inc.: The DNN Expandable Text/HTML module allows you to display multiple text items with the ability to expand and collapse individual items.FarajsWeb2Project: This project is intended to design a Web2.0 website for 7COM0203 ModuleGeminorum Software Contacts for DotNetNuke: A simple contact manager for DotNetNuke.GitText: Test olyGoDarting by Harsh Maurya: Darts Game developed in WPF. requires .Net Framework 4.0Info Gempa BMKG: Aplikasi pembaca informasi gempa BMKGMassive encryption of files: "Massive Encrypt" allows you to encrypt or rename many files at once. Of course you can decrypt later encrypted files!Metal Player: Simple and easy to use, Metal Player has basic multimedia player functions, and some new functions that will enjoy you.NAntDefineTasks: NAnt Define Tasks allows you to define NAnt tasks in terms of other NAnt tasks, instead of having to write any C# code. Nebulosa: Nebulosa is a complete engine to create a complete websitesNigeria Single Mothers: This website project helps single mothers in Nigeria share ideas on how to raise children given the socio-economic and cultural challenges they face.PCV_Clinic_Pro: PCVClinicPro is a software proRendering.NET: Rendering.NET is an abstraction for any visualization device and over several APIs like OpenGL, DirectX, XNA, WebGL, WPF, Silverlight, Mobile DirectX, etc.RLA: A template for illustrate a MVC2 websiteSecure Password Recovery for DotNetNuke by IowaComputerGurus Inc.: IowaComputerGurus's Secure Password Recovery module is the next step in preventing user passwords from being sent via e-mail!SimpleSum: This calculates a simple sum using Visual Basic.SiteCetic: Sitio de CETIC Social Learning: Social Learning Project for BC 2012Towards a generic DSL for modeling page types in WCMSs: An exploration of creating DSLs to facilitate the creation of page models in WCMSs using VMSDK. The concepts of PIM, PSM, DSL, M2M, and M2T will be explored.TrafficArchives: TrafficArchives is a two people group of TrafficArchives team, in this project ,we will use asp.net do Traffic Archives information manager system.UnivDevs: university test developmentUppityUp: UppityUp is a simple and light-weight tray application which monitors a remote server and shows a notification when it comes online. This is useful when you need to connect to a server that is currently down and you want to be notified the moment it becomes available.uurrooster: Hier wordt nog aan gewerktUWE Computer Science: A collection of all work submitted and completed during my course at UWE - Bristol.ViewMyDeals: This Site is all about sharing dramatic deals and offers of several products using Promotional codes and vouchers .WebUntis4Win8: WebUntis4Win8X.MetaWeblog.Model: This is a model for MetaWeblog API. Detail info at: http://xmlrpc.scripting.com/metaWeblogApi.html http://en.wikipedia.org/wiki/MetaWeblogXPath execution utility: CommonXPath is a utility to execute an XPath expression on some XML and see the result.

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• MINSCN?Cache Fusion Read Consistent

  - by Liu Maclean(???)

  ????? ???Ask Maclean Home ???  RAC ? Past Image PI????, ?????????,???11.2.0.3 2 Node RAC??????????: SQL> select * from v$version; BANNER -------------------------------------------------------------------------------- Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production PL/SQL Release 11.2.0.3.0 - Production CORE 11.2.0.3.0 Production TNS for Linux: Version 11.2.0.3.0 - Production NLSRTL Version 11.2.0.3.0 - Production SQL> select * from global_name; GLOBAL_NAME -------------------------------------------------------------------------------- www.oracledatabase12g.com SQL> drop table test purge; Table dropped. SQL> alter system flush buffer_cache; System altered. SQL> create table test(id number); insert into test values(1); insert into test values(2); commit; /* ???? rowid??TEST????2????????? */ select dbms_rowid.rowid_block_number(rowid),dbms_rowid.rowid_relative_fno(rowid) from test; DBMS_ROWID.ROWID_BLOCK_NUMBER(ROWID) DBMS_ROWID.ROWID_RELATIVE_FNO(ROWID) ------------------------------------ ------------------------------------                                89233                                    1                                89233                                    1 SQL> alter system flush buffer_cache; System altered. Instance 1 Session A ??UPDATE??: SQL> update test set id=id+1 where id=1; 1 row updated. Instance 1 Session B ??x$BH buffer header?? ?? ??Buffer??? SQL> select state,cr_scn_bas from x$bh where file#=1 and dbablk=89233 and state!=0;      STATE CR_SCN_BAS ---------- ----------          1          0          3    1227595 X$BH ??? STATE????Buffer???, ???????: STATE NUMBER KCBBHFREE 0 buffer free KCBBHEXLCUR 1 buffer current (and if DFS locked X) KCBBHSHRCUR 2 buffer current (and if DFS locked S) KCBBHCR 3 buffer consistant read KCBBHREADING 4 Being read KCBBHMRECOVERY 5 media recovery (current & special) KCBBHIRECOVERY 6 Instance recovery (somewhat special) ????????????? : state =1 Xcurrent ? state=2 Scurrent ? state=3 CR ??? Instance 2  ?? ????????????? ,???? gc current block 2 way  ??Current Block ??? Instance 2, ?? Instance 1 ??”Current Block” Convert ? Past Image: Instance 2 Session C SQL> update test set id=id+1 where id=2; 1 row updated. Instance 2 Session D SQL> select state,cr_scn_bas from x$bh where file#=1 and dbablk=89233 and state!=0; STATE CR_SCN_BAS ---------- ---------- 1 0 3 1227641 3 1227638 STATE =1 ?Xcurrent block???? Instance 2 , ??? Instance 1 ??? GC??: Instance 1 Session B SQL> select state,cr_scn_bas from x$bh where file#=1 and dbablk=89233 and state!=0;      STATE CR_SCN_BAS ---------- ----------          3    1227641          3    1227638          8          0          3    1227595 ???????, ??????Instance 1??session A????TEST??SELECT??? ,????? 3? State=3?CR ? ??????1?: Instance 1 session A ?????UPDATE? session SQL> alter session set events '10046 trace name context forever,level 8:10708 trace name context forever,level 103: trace[rac.*] disk high'; Session altered. SQL> select * from test;         ID ----------          2          2 select state,cr_scn_bas from x$bh where file#=1 and dbablk=89233 and state!=0;       STATE CR_SCN_BAS ---------- ----------          3    1227716          3    1227713          8          0 ?????????v$BH ????CR????,?????SELECT??? CR????????,???????? ?????????? ??X$BH?????? , ?????CR??SCN Version???: 1227641?1227638?1227595, ?SELECT?????? 2???SCN version?CR? 1227716? 1227713 ???, Oracle????????? ?????????SELECT??????event 10708? rac.*???TRACE,??????TRACE??: PARSING IN CURSOR #140444679938584 len=337 dep=1 uid=0 oct=3 lid=0 tim=1335698913632292 hv=3345277572 ad='bc0e68c8' sqlid='baj7tjm3q9sn4' SELECT /* OPT_DYN_SAMP */ /*+ ALL_ROWS IGNORE_WHERE_CLAUSE NO_PARALLEL(SAMPLESUB) opt_param('parallel_execution_enabled', 'false') NO_PARALLEL_INDEX(SAMPLESUB) NO_SQL_TUNE */ NVL(SUM(C1),0), NVL(SUM(C2),0) FROM (SELECT /*+ NO_PARALLEL("TEST") FULL("TEST") NO_PARALLEL_INDEX("TEST") */ 1 AS C1, 1 AS C2 FROM "SYS"."TEST" "TEST") SAMPLESUB END OF STMT PARSE #140444679938584:c=1000,e=27630,p=0,cr=0,cu=0,mis=1,r=0,dep=1,og=1,plh=1950795681,tim=1335698913632252 EXEC #140444679938584:c=0,e=44,p=0,cr=0,cu=0,mis=0,r=0,dep=1,og=1,plh=1950795681,tim=1335698913632390 *** 2012-04-29 07:28:33.632 kclscrs: req=0 block=1/89233 *** 2012-04-29 07:28:33.632 kclscrs: bid=1:3:1:0:7:80:1:0:4:0:0:0:1:2:4:1:26:0:0:0:70:1a:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:4:3:2:1:2:0:3f:0:1c:86:2d:4:0:0:0:0:a2:3c:7c:b:70:1a:0:0:0:0:1:0:7a:f8:76:1d:1:2:dc:5:a9:fe:17:75:0:0:0:0:0:0:0:0:0:0:0:0:63:e5:0:0:0:0:0:0:10:0:0:0 2012-04-29 07:28:33.632578 : kjbcrc[0x15c91.1 76896.0][9] 2012-04-29 07:28:33.632616 : GSIPC:GMBQ: buff 0xba1e8f90, queue 0xbb79f278, pool 0x60013fa0, freeq 1, nxt 0xbb79f278, prv 0xbb79f278 2012-04-29 07:28:33.632634 : kjbmscrc(0x15c91.1)seq 0x2 reqid=0x1c(shadow 0xb4bb4458,reqid x1c)mas@2(infosz 200)(direct 1) 2012-04-29 07:28:33.632654 : kjbsentscn[0x0.12bbc1][to 2] 2012-04-29 07:28:33.632669 : GSIPC:SENDM: send msg 0xba1e9000 dest x20001 seq 24026 type 32 tkts xff0000 mlen x17001a0 2012-04-29 07:28:33.633385 : GSIPC:KSXPCB: msg 0xba1e9000 status 30, type 32, dest 2, rcvr 1 *** 2012-04-29 07:28:33.633 kclwcrs: wait=0 tm=689 *** 2012-04-29 07:28:33.633 kclwcrs: got 1 blocks from ksxprcv WAIT #140444679938584: nam='gc cr block 2-way' ela= 689 p1=1 p2=89233 p3=1 obj#=76896 tim=1335698913633418 2012-04-29 07:28:33.633490 : kjbcrcomplete[0x15c91.1 76896.0][0] 2012-04-29 07:28:33.633510 : kjbrcvdscn[0x0.12bbc1][from 2][idx 2012-04-29 07:28:33.633527 : kjbrcvdscn[no bscn <= rscn 0x0.12bbc1][from 2] *** 2012-04-29 07:28:33.633 kclwcrs: req=0 typ=cr(2) wtyp=2hop tm=689 ??TRACE???? ?????????TEST??????, ???????Dynamic Sampling?????,???????TEST?? CR???,???????’gc cr block 2-way’ ??: 2012-04-29 07:28:33.632654 : kjbsentscn[0x0.12bbc1][to 2] 12bbc1= 1227713  ???X$BH????CR???,kjbsentscn[0x0.12bbc1][to 2] ????? ? Instance 2 ???SCN=12bbc1=1227713   DBA=0x15c91.1 76896.0 ?  CR Request(obj#=76896) ??kjbrcvdscn????? [no bscn <= rscn 0x0.12bbc1][from 2] ,??? ??receive? SCN Version =12bbc1 ???Best Version CR Server Arch ??????????????????SELECT??: PARSING IN CURSOR #140444682869592 len=18 dep=0 uid=0 oct=3 lid=0 tim=1335698913635874 hv=1689401402 ad='b1a188f0' sqlid='c99yw1xkb4f1u' select * from test END OF STMT PARSE #140444682869592:c=4999,e=34017,p=0,cr=7,cu=0,mis=1,r=0,dep=0,og=1,plh=1357081020,tim=1335698913635870 EXEC #140444682869592:c=0,e=23,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=1,plh=1357081020,tim=1335698913635939 WAIT #140444682869592: nam='SQL*Net message to client' ela= 7 driver id=1650815232 #bytes=1 p3=0 obj#=0 tim=1335698913636071 *** 2012-04-29 07:28:33.636 kclscrs: req=0 block=1/89233 *** 2012-04-29 07:28:33.636 kclscrs: bid=1:3:1:0:7:83:1:0:4:0:0:0:1:2:4:1:26:0:0:0:70:1a:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:4:3:2:1:2:0:2:0:1c:86:2d:4:0:0:0:0:a2:3c:7c:b:70:1a:0:0:0:0:1:0:7d:f8:76:1d:1:2:dc:5:a9:fe:17:75:0:0:0:0:0:0:0:0:0:0:0:0:63:e5:0:0:0:0:0:0:10:0:0:0 2012-04-29 07:28:33.636209 : kjbcrc[0x15c91.1 76896.0][9] 2012-04-29 07:28:33.636228 : GSIPC:GMBQ: buff 0xba0e5d50, queue 0xbb79f278, pool 0x60013fa0, freeq 1, nxt 0xbb79f278, prv 0xbb79f278 2012-04-29 07:28:33.636244 : kjbmscrc(0x15c91.1)seq 0x3 reqid=0x1d(shadow 0xb4bb4458,reqid x1d)mas@2(infosz 200)(direct 1) 2012-04-29 07:28:33.636252 : kjbsentscn[0x0.12bbc4][to 2] 2012-04-29 07:28:33.636358 : GSIPC:SENDM: send msg 0xba0e5dc0 dest x20001 seq 24029 type 32 tkts xff0000 mlen x17001a0 2012-04-29 07:28:33.636861 : GSIPC:KSXPCB: msg 0xba0e5dc0 status 30, type 32, dest 2, rcvr 1 *** 2012-04-29 07:28:33.637 kclwcrs: wait=0 tm=865 *** 2012-04-29 07:28:33.637 kclwcrs: got 1 blocks from ksxprcv WAIT #140444682869592: nam='gc cr block 2-way' ela= 865 p1=1 p2=89233 p3=1 obj#=76896 tim=1335698913637294 2012-04-29 07:28:33.637356 : kjbcrcomplete[0x15c91.1 76896.0][0] 2012-04-29 07:28:33.637374 : kjbrcvdscn[0x0.12bbc4][from 2][idx 2012-04-29 07:28:33.637389 : kjbrcvdscn[no bscn <= rscn 0x0.12bbc4][from 2] *** 2012-04-29 07:28:33.637 kclwcrs: req=0 typ=cr(2) wtyp=2hop tm=865 ???, “SELECT * FROM TEST”??????’gc cr block 2-way’??:2012-04-29 07:28:33.637374 : kjbrcvdscn[0x0.12bbc4][from 2][idx 2012-04-29 07:28:33.637389 : kjbrcvdscn[no bscn ??Foreground Process? Remote LMS??got?? SCN=1227716 Version?CR, ??? ?????X$BH ?????scn??? ??????????Instance 1????2?SCN???CR?, ???????????Instance 1 Buffer Cache?? ??SCN Version ???CR ??????? ?????????: SQL> alter system set "_enable_minscn_cr"=false scope=spfile; System altered. SQL> alter system set "_db_block_max_cr_dba"=20 scope=spfile; System altered. SQL> startup force; ORA-32004: obsolete or deprecated parameter(s) specified for RDBMS instance ORACLE instance started. Total System Global Area 1570009088 bytes Fixed Size 2228704 bytes Variable Size 989859360 bytes Database Buffers 570425344 bytes Redo Buffers 7495680 bytes Database mounted. Database opened. ???? “_enable_minscn_cr”=false ? “_db_block_max_cr_dba”=20 ???RAC????, ??????: ?Instance 2 Session C ?update??????? ?????Instance 1 ????? ,????Instance 1?Request CR SQL> update test set id=id+1 where id=2; -- Instance 2 1 row updated. SQL> select * From test; -- Instance 1 ID ---------- 1 2 ??? Instance 1? X$BH?? select state,cr_scn_bas from x$bh where file#=1 and dbablk=89233 and state!=0;  STATE CR_SCN_BAS ---------- ---------- 3 1273080 3 1273071 3 1273041 3 1273039 8 0 SQL> update test set id=id+1 where id=3; 1 row updated. SQL> select * From test; ID ---------- 1 2 SQL> select state,cr_scn_bas from x$bh where file#=1 and dbablk=89233 and state!=0; STATE CR_SCN_BAS ---------- ---------- 3 1273091 3 1273080 3 1273071 3 1273041 3 1273039 8 0 ................... SQL> select state,cr_scn_bas from x$bh where file#=1 and dbablk=89233 and state!=0; STATE CR_SCN_BAS ---------- ---------- 3 1273793 3 1273782 3 1273780 3 1273769 3 1273734 3 1273715 3 1273691 3 1273679 3 1273670 3 1273643 3 1273635 3 1273623 3 1273106 3 1273091 3 1273080 3 1273071 3 1273041 3 1273039 3 1273033 19 rows selected. SQL> select state,cr_scn_bas from x$bh where file#=1 and dbablk=89233 and state!=0; STATE CR_SCN_BAS ---------- ---------- 3 1274993 ????? ???? “_enable_minscn_cr”(enable/disable minscn optimization for CR)=false ? “_db_block_max_cr_dba”=20 (Maximum Allowed Number of CR buffers per dba) 2? ??? ????? Instance 1 ??????????? ?? 19????CR?? “_enable_minscn_cr”?11g??????????,???Oracle????CR????SCN,?Foreground Process Receive????????????(SCN??)?SCN Version CR Block??????CBC?? SCN??????CR? , ?????????Buffer Cache??????? ????SCN Version?CR????,????? ?????????? ?????Snap_Scn ?? SCN?? ?????????Current SCN, ??????CR??????????????????????, ????Buffer Cache? ?????????? CR?????????, ?????? “_db_block_max_cr_dba” ???????, ???????????20 ,??????Buffer Cache?????19????CR?; ???”_db_block_max_cr_dba” ???????6 , ?????Buffer cache????????CR ???????6?? ??”_enable_minscn_cr” ??CR???MINSCN ??????, ?????????CR???????, ????? Foreground Process??????CR Request , ?? Holder Instance LMS ?build?? BEST CR ??, ?????????

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• C#/.NET Little Wonders: Interlocked CompareExchange()

  - by James Michael Hare

  Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. Two posts ago, I discussed the Interlocked Add(), Increment(), and Decrement() methods (here) for adding and subtracting values in a thread-safe, lightweight manner.  Then, last post I talked about the Interlocked Read() and Exchange() methods (here) for safely and efficiently reading and setting 32 or 64 bit values (or references).  This week, we’ll round out the discussion by talking about the Interlocked CompareExchange() method and how it can be put to use to exchange a value if the current value is what you expected it to be. Dirty reads can lead to bad results Many of the uses of Interlocked that we’ve explored so far have centered around either reading, setting, or adding values.  But what happens if you want to do something more complex such as setting a value based on the previous value in some manner? Perhaps you were creating an application that reads a current balance, applies a deposit, and then saves the new modified balance, where of course you’d want that to happen atomically.  If you read the balance, then go to save the new balance and between that time the previous balance has already changed, you’ll have an issue!  Think about it, if we read the current balance as $400, and we are applying a new deposit of $50.75, but meanwhile someone else deposits $200 and sets the total to $600, but then we write a total of $450.75 we’ve lost $200! Now, certainly for int and long values we can use Interlocked.Add() to handles these cases, and it works well for that.  But what if we want to work with doubles, for example?  Let’s say we wanted to add the numbers from 0 to 99,999 in parallel.  We could do this by spawning several parallel tasks to continuously add to a total: 1: double total = 0; 2:  3: Parallel.For(0, 10000, next => 4: { 5: total += next; 6: }); Were this run on one thread using a standard for loop, we’d expect an answer of 4,999,950,000 (the sum of all numbers from 0 to 99,999).  But when we run this in parallel as written above, we’ll likely get something far off.  The result of one of my runs, for example, was 1,281,880,740.  That is way off!  If this were banking software we’d be in big trouble with our clients.  So what happened?  The += operator is not atomic, it will read in the current value, add the result, then store it back into the total.  At any point in all of this another thread could read a “dirty” current total and accidentally “skip” our add.   So, to clean this up, we could use a lock to guarantee concurrency: 1: double total = 0.0; 2: object locker = new object(); 3:  4: Parallel.For(0, count, next => 5: { 6: lock (locker) 7: { 8: total += next; 9: } 10: }); Which will give us the correct result of 4,999,950,000.  One thing to note is that locking can be heavy, especially if the operation being locked over is trivial, or the life of the lock is a high percentage of the work being performed concurrently.  In the case above, the lock consumes pretty much all of the time of each parallel task – and the task being locked on is relatively trivial. Now, let me put in a disclaimer here before we go further: For most uses, lock is more than sufficient for your needs, and is often the simplest solution!    So, if lock is sufficient for most needs, why would we ever consider another solution?  The problem with locking is that it can suspend execution of your thread while it waits for the signal that the lock is free.  Moreover, if the operation being locked over is trivial, the lock can add a very high level of overhead.  This is why things like Interlocked.Increment() perform so well, instead of locking just to perform an increment, we perform the increment with an atomic, lockless method. As with all things performance related, it’s important to profile before jumping to the conclusion that you should optimize everything in your path.  If your profiling shows that locking is causing a high level of waiting in your application, then it’s time to consider lighter alternatives such as Interlocked. CompareExchange() – Exchange existing value if equal some value So let’s look at how we could use CompareExchange() to solve our problem above.  The general syntax of CompareExchange() is: T CompareExchange<T>(ref T location, T newValue, T expectedValue) If the value in location == expectedValue, then newValue is exchanged.  Either way, the value in location (before exchange) is returned. Actually, CompareExchange() is not one method, but a family of overloaded methods that can take int, long, float, double, pointers, or references.  It cannot take other value types (that is, can’t CompareExchange() two DateTime instances directly).  Also keep in mind that the version that takes any reference type (the generic overload) only checks for reference equality, it does not call any overridden Equals(). So how does this help us?  Well, we can grab the current total, and exchange the new value if total hasn’t changed.  This would look like this: 1: // grab the snapshot 2: double current = total; 3:  4: // if the total hasn’t changed since I grabbed the snapshot, then 5: // set it to the new total 6: Interlocked.CompareExchange(ref total, current + next, current); So what the code above says is: if the amount in total (1st arg) is the same as the amount in current (3rd arg), then set total to current + next (2nd arg).  This check and exchange pair is atomic (and thus thread-safe). This works if total is the same as our snapshot in current, but the problem, is what happens if they aren’t the same?  Well, we know that in either case we will get the previous value of total (before the exchange), back as a result.  Thus, we can test this against our snapshot to see if it was the value we expected: 1: // if the value returned is != current, then our snapshot must be out of date 2: // which means we didn't (and shouldn't) apply current + next 3: if (Interlocked.CompareExchange(ref total, current + next, current) != current) 4: { 5: // ooops, total was not equal to our snapshot in current, what should we do??? 6: } So what do we do if we fail?  That’s up to you and the problem you are trying to solve.  It’s possible you would decide to abort the whole transaction, or perhaps do a lightweight spin and try again.  Let’s try that: 1: double current = total; 2:  3: // make first attempt... 4: if (Interlocked.CompareExchange(ref total, current + i, current) != current) 5: { 6: // if we fail, go into a spin wait, spin, and try again until succeed 7: var spinner = new SpinWait(); 8:  9: do 10: { 11: spinner.SpinOnce(); 12: current = total; 13: } 14: while (Interlocked.CompareExchange(ref total, current + i, current) != current); 15: } 16:  This is not trivial code, but it illustrates a possible use of CompareExchange().  What we are doing is first checking to see if we succeed on the first try, and if so great!  If not, we create a SpinWait and then repeat the process of SpinOnce(), grab a fresh snapshot, and repeat until CompareExchnage() succeeds.  You may wonder why not a simple do-while here, and the reason it’s more efficient to only create the SpinWait until we absolutely know we need one, for optimal efficiency. Though not as simple (or maintainable) as a simple lock, this will perform better in many situations.  Comparing an unlocked (and wrong) version, a version using lock, and the Interlocked of the code, we get the following average times for multiple iterations of adding the sum of 100,000 numbers: 1: Unlocked money average time: 2.1 ms 2: Locked money average time: 5.1 ms 3: Interlocked money average time: 3 ms So the Interlocked.CompareExchange(), while heavier to code, came in lighter than the lock, offering a good compromise of safety and performance when we need to reduce contention. CompareExchange() - it’s not just for adding stuff… So that was one simple use of CompareExchange() in the context of adding double values -- which meant we couldn’t have used the simpler Interlocked.Add() -- but it has other uses as well. If you think about it, this really works anytime you want to create something new based on a current value without using a full lock.  For example, you could use it to create a simple lazy instantiation implementation.  In this case, we want to set the lazy instance only if the previous value was null: 1: public static class Lazy<T> where T : class, new() 2: { 3: private static T _instance; 4:  5: public static T Instance 6: { 7: get 8: { 9: // if current is null, we need to create new instance 10: if (_instance == null) 11: { 12: // attempt create, it will only set if previous was null 13: Interlocked.CompareExchange(ref _instance, new T(), (T)null); 14: } 15:  16: return _instance; 17: } 18: } 19: } So, if _instance == null, this will create a new T() and attempt to exchange it with _instance.  If _instance is not null, then it does nothing and we discard the new T() we created. This is a way to create lazy instances of a type where we are more concerned about locking overhead than creating an accidental duplicate which is not used.  In fact, the BCL implementation of Lazy<T> offers a similar thread-safety choice for Publication thread safety, where it will not guarantee only one instance was created, but it will guarantee that all readers get the same instance.  Another possible use would be in concurrent collections.  Let’s say, for example, that you are creating your own brand new super stack that uses a linked list paradigm and is “lock free”.  We could use Interlocked.CompareExchange() to be able to do a lockless Push() which could be more efficient in multi-threaded applications where several threads are pushing and popping on the stack concurrently. Yes, there are already concurrent collections in the BCL (in .NET 4.0 as part of the TPL), but it’s a fun exercise!  So let’s assume we have a node like this: 1: public sealed class Node<T> 2: { 3: // the data for this node 4: public T Data { get; set; } 5:  6: // the link to the next instance 7: internal Node<T> Next { get; set; } 8: } Then, perhaps, our stack’s Push() operation might look something like: 1: public sealed class SuperStack<T> 2: { 3: private volatile T _head; 4:  5: public void Push(T value) 6: { 7: var newNode = new Node<int> { Data = value, Next = _head }; 8:  9: if (Interlocked.CompareExchange(ref _head, newNode, newNode.Next) != newNode.Next) 10: { 11: var spinner = new SpinWait(); 12:  13: do 14: { 15: spinner.SpinOnce(); 16: newNode.Next = _head; 17: } 18: while (Interlocked.CompareExchange(ref _head, newNode, newNode.Next) != newNode.Next); 19: } 20: } 21:  22: // ... 23: } Notice a similar paradigm here as with adding our doubles before.  What we are doing is creating the new Node with the data to push, and with a Next value being the original node referenced by _head.  This will create our stack behavior (LIFO – Last In, First Out).  Now, we have to set _head to now refer to the newNode, but we must first make sure it hasn’t changed! So we check to see if _head has the same value we saved in our snapshot as newNode.Next, and if so, we set _head to newNode.  This is all done atomically, and the result is _head’s original value, as long as the original value was what we assumed it was with newNode.Next, then we are good and we set it without a lock!  If not, we SpinWait and try again. Once again, this is much lighter than locking in highly parallelized code with lots of contention.  If I compare the method above with a similar class using lock, I get the following results for pushing 100,000 items: 1: Locked SuperStack average time: 6 ms 2: Interlocked SuperStack average time: 4.5 ms So, once again, we can get more efficient than a lock, though there is the cost of added code complexity.  Fortunately for you, most of the concurrent collection you’d ever need are already created for you in the System.Collections.Concurrent (here) namespace – for more information, see my Little Wonders – The Concurent Collections Part 1 (here), Part 2 (here), and Part 3 (here). Summary We’ve seen before how the Interlocked class can be used to safely and efficiently add, increment, decrement, read, and exchange values in a multi-threaded environment.  In addition to these, Interlocked CompareExchange() can be used to perform more complex logic without the need of a lock when lock contention is a concern. The added efficiency, though, comes at the cost of more complex code.  As such, the standard lock is often sufficient for most thread-safety needs.  But if profiling indicates you spend a lot of time waiting for locks, or if you just need a lock for something simple such as an increment, decrement, read, exchange, etc., then consider using the Interlocked class’s methods to reduce wait. Technorati Tags: C#,CSharp,.NET,Little Wonders,Interlocked,CompareExchange,threading,concurrency

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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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• Syntax error in aggregate argument: Expecting a single column argument with possible 'Child' qualifier.

  - by Rushabh

  DataTable distinctTable = dTable.DefaultView.ToTable(true,"ITEM_NO","ITEM_STOCK"); DataTable dtSummerized = new DataTable("SummerizedResult"); dtSummerized.Columns.Add("ITEM_NO",typeof(string)); dtSummerized.Columns.Add("ITEM_STOCK",typeof(double)); int count=0; foreach(DataRow dRow in distinctTable.Rows) { count++; //string itemNo = Convert.ToString(dRow[0]); double TotalItem = Convert.ToDouble(dRow[1]); string TotalStock = dTable.Compute("sum(" + TotalItem + ")", "ITEM_NO=" + dRow["ITEM_NO"].ToString()).ToString(); dtSummerized.Rows.Add(count,dRow["ITEM_NO"],TotalStock); } Error Message: Syntax error in aggregate argument: Expecting a single column argument with possible 'Child' qualifier. Do anyone can help me out? Thanks.

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• How do I join these queries?

  - by GregoryD

  query1: SELECT category.id, category.name, category.level, category.description, category.cat1, category.cat2, category.cat3, category.cat4, category.pri_color, category.sec_color, category.last_report AS report_id FROM category, reports_category_layout WHERE category.id = reports_category_layout.catID AND reports_category_layout.site_code = 'las' query2: SELECT DISTINCT category.id, COUNT(forum.id) AS posts, SUM(forum.view) AS views FROM category, forum WHERE category.id = forum.catID AND forum.approved = 'yes' AND forum.site_code = 'las' GROUP BY category.id query3: SELECT forum.catID, forum.title, forum.paragraph, forum.created, users.alias, forum.userID FROM forum, users, forum_cache WHERE forum.catID = forum_cache.catID AND forum.id = forum_cache.last_report AND users.id = forum.userID AND forum.approved = 'yes' Essentially, I am unsure about the syntax to join these properly. I have written a query that simply joins them, but in the case that the forum cache table contains an unapproved forum id, it will simply not return the entire row. what I really need is for query1 and query2 to be left joined on the category id, and for query 3 to be left outer joined on id = catID.

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• Calculated control on subform based on current record

  - by rtochip

  I have the following: main form "customer" from a "customer" table. subform "invoices" with fields "invoice date", "invoice amount" "customer id" etc. from a table "invoices" whenever user clicks or goes to a record in the "invoices" sub form. I would like a "total so far" control to calculate the sum of the "invoices amount" up until the date of the current record being "clicked" or selected. i.e. for customer microsoft with invoices: 1) may 2 09, $150 2) may 3 09, $200 3) may 4 09, $500 If user clicks on record 2), "total so far" should show $350 If user clicks on record 1), "total so far" should show $150 If user clicks on record 3), "total so far" should show $850 Currently, I am using DSum function on an event "OnCurrent" in the subform "invoices" to set the "total so far" value. Is this method slow, inefficient? Any other simpler,cleaner,more elegant,faster, efficient method using ms access features? I want the "invoices" subform to show ALL the invoices for this customer no matter which record is clicked.

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• A detail question when applying genetic algorithm to traveling salesman

  - by burrough

  I read various stuff on this and understand the principle and concepts involved, however, none of paper mentions the details of how to calculate the fitness of a chromosome (which represents a route) involving adjacent cities (in the chromosome) that are not directly connected by an edge (in the graph). For example, given a chromosome 1|3|2|8|4|5|6|7, in which each gene represents the index of a city on the graph/map, how do we calculate its fitness (i.e. the total sum of distances traveled) if, say, there is no direct edge/link between city 2 and 8. Do we follow some sort of greedy algorithm to work out a route between 2 and 8, and add the distance of this route to the total? This problem seems pretty common when applying GA to TSP. Anyone who's done it before please share your experience. Thanks.

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• Properly handling possible System.NullReferenceException in lambda expressions

  - by Travis Johnson

  Here's the query in question return _projectDetail.ExpenditureDetails .Where(detail => detail.ProgramFund == _programFund && detail.Expenditure.User == _creditCardHolder) .Sum(detail => detail.ExpenditureAmounts.FirstOrDefault( amount => amount.isCurrent && !amount.requiresAudit) .CommittedMonthlyRecord.ProjectedEac); Table Structure ProjectDetails (1 to Many) ExpenditureDetails ExpenditureDetails (1 to Many) ExpenditureAmounts ExpenditureAmounts (1 to 1) CommittedMonthlyRecords ProjectedEac is a decimal field on the CommittedMonthlyRecords. The problem I discovered in a Unit test (albeit an unlikely event), that the following line could be null: detail.ExpenditureAmounts.FirstOrDefault( amount => amount.isCurrent && !amount.requiresAudit) My original query was a nested loop, in where I would be making multiple trips to the database, something I don't want to repeat. I've looked in to what seemed like some similar questions here, but the solution didn't seem to fit. Any ideas?

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• How to retrieve row count of one-to-many relation while also including original entity?

  - by kaa

  Say I have two entities Foo and Bar where Foo has-many Bar's, class Foo { int ImportantNumber { get; set; } IEnumerable<Bar> Bars { get; set; } } class FooDTO { Foo Foo { get; set; } int BarCount { get; set; } } How can I efficiently sum up the number of Bars per Foo in a DTO using a single query, preferrably only with the Criteria interface. I have tried any number of ways to get the original entity out of a query with ´SetProjection´ but no luck. The current theory is to do something like SELECT Foo.*, BarCounts.counts FROM Foo LEFT JOIN ( SELECT fooId, COUNT(*) as counts FROM Bar GROUP BY fooId ) AS BarCounts ON Foo.id=BarCounts.fooId but with Criterias, and I just can't seem to figure out how.

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• Performance of file operations on thousands of files on NTFS vs HFS, ext3, others

  - by peterjmag

  [Crossposted from my Ask HN post. Feel free to close it if the question's too broad for superuser.] This is something I've been curious about for years, but I've never found any good discussions on the topic. Of course, my Google-fu might just be failing me... I often deal with projects involving thousands of relatively small files. This means that I'm frequently performing operations on all of those files or a large subset of them—copying the project folder elsewhere, deleting a bunch of temporary files, etc. Of all the machines I've worked on over the years, I've noticed that NTFS handles these tasks consistently slower than HFS on a Mac or ext3/ext4 on a Linux box. However, as far as I can tell, the raw throughput isn't actually slower on NTFS (at least not significantly), but the delay between each individual file is just a tiny bit longer. That little delay really adds up for thousands of files. (Side note: From what I've read, this is one of the reasons git is such a pain on Windows, since it relies so heavily on the file system for its object database.) Granted, my evidence is merely anecdotal—I don't currently have any real performance numbers, but it's something that I'd love to test further (perhaps with a Mac dual-booting into Windows). Still, my geekiness insists that someone out there already has. Can anyone explain this, or perhaps point me in the right direction to research it further myself?

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• Computing MD5SUM of large files in C#

  - by spkhaira

  I am using following code to compute MD5SUM of a file - byte[] b = System.IO.File.ReadAllBytes(file); string sum = BitConverter.ToString(new MD5CryptoServiceProvider().ComputeHash(b)); This works fine normally, but if I encounter a large file (~1GB) - e.g. an iso image or a DVD VOB file - I get an Out of Memory exception. Though, I am able to compute the MD5SUM in cygwin for the same file in about 10secs. Please suggest how can I get this to work for big files in my program. Thanks

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• F# Static Member Type Constraints

  - by Stephen Swensen

  I'm trying to define a function, factorize, which uses structural type constraints (requires static members Zero, One, +, and /) similar to Seq.sum so that it can be used with int, long, bigint, etc. I can't seem to get the syntax right, and can't find a lot of resources on the subject. This is what I have, please help. let inline factorize (n:^NUM) = ^NUM : (static member get_Zero: unit->(^NUM)) ^NUM : (static member get_One: unit->(^NUM)) let rec factorize (n:^NUM) (j:^NUM) (flist: ^NUM list) = if n = ^NUM.One then flist elif n % j = ^NUM.Zero then factorize (n/j) (^NUM.One + ^NUM.One) (j::flist) else factorize n (j + ^NUM.One) (flist) factorize n (^NUM.One + ^NUM.One) []

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• What's up with stat on MacOSX/Darwin? Or filesystems without names...

  - by Charles Stewart

  In response to a question I asked on SO, Give the mount point of a path, one respondant suggested using stat to get the device name associated with the volume of a given path. This works nicely on Linux, but gives crazy results on MacOSX 10.4. For my system, df and mount give: cas cas$ df Filesystem 512-blocks Used Avail Capacity Mounted on /dev/disk0s3 58342896 49924456 7906440 86% / devfs 194 194 0 100% /dev fdesc 2 2 0 100% /dev <volfs> 1024 1024 0 100% /.vol automount -nsl [166] 0 0 0 100% /Network automount -fstab [170] 0 0 0 100% /automount/Servers automount -static [170] 0 0 0 100% /automount/static /dev/disk2s1 163577856 23225520 140352336 14% /Volumes/Snapshot /dev/disk2s2 409404102 5745938 383187960 1% /Volumes/Sparse cas cas$ mount /dev/disk0s3 on / (local, journaled) devfs on /dev (local) fdesc on /dev (union) <volfs> on /.vol automount -nsl [166] on /Network (automounted) automount -fstab [170] on /automount/Servers (automounted) automount -static [170] on /automount/static (automounted) /dev/disk2s1 on /Volumes/Snapshot (local, nodev, nosuid, journaled) /dev/disk2s2 on /Volumes/Sparse (asynchronous, local, nodev, nosuid) Trying to get the devices from the mount points, though: cas cas$ df | grep -e/ | awk '{print $NF}' | while read line; do echo $line $(stat -f"%Sdr" $line); done / disk0s3r /dev ???r /dev ???r /.vol ???r /Network ???r /automount/Servers ???r /automount/static ???r /Volumes/Snapshot disk2s1r /Volumes/Sparse disk2s2r Here, I'm feeding each of the mount points scraped from df to stat, outputting the results of the "%Sdr" format string, which is supposed to be the device name: Cf. stat(1) man page: The special output specifier S may be used to indicate that the output, if applicable, should be in string format. May be used in combination with: ... dr Display actual device name. What's going on? Is it a bug in stat, or some Darwin VFS weirdness? Postscript Per Andrew McGregor, try passing "%Sd" to stat for more weirdness. It lists some apparently arbitrary subset of files from CWD...

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• Hierarchy based aggregation

  - by Ganapathy Subramaniam

  I have a hierarchy table in SQL Server 2005 which contains employees - managers - department - location - state. Sample table for hierarchy table: ID Name ParentID Type 1 PA NULL 0 (group) 2 Pittsburgh 1 1 (subgroup) 3 Accounts 2 1 4 Alex 3 2 (employee) 5 Robin 3 2 6 HR 2 1 7 Robert 6 2 Second one is fact table which contains employee salary details ID and Salary. Sample data for fact table: ID Salary 4 6000 5 5000 7 4000 Is there any good to way to display the hierarchy from hierarchy table with aggregated sum of salary based on employees. Expected result is like Name Salary PA 15000 (Pittsburgh + others(if any)) Pittusburgh 15000 (Accounts + HR) Accounts 11000 (Alex + Robin) Alex 6000 (direct values) Robin 5000 HR 4000 Robert 4000 In my production environment, hierarchy table may contain 23000+ rows and fact table may contain 300,000+ rows. So, I thought of providing any level of groupid to the query to retrieve just its children and its corresponding aggregated value. Any better solution?

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• How to configure maximum number of channels in WCF?

  - by Hemant

  Consider following code which calls a calculator service: static void Main (string[] args) { for (int i = 0; i < 32; i++) { ThreadPool.QueueUserWorkItem (o => { var client = new CalcServiceClient (); client.Open (); while (true) { var sum = client.Add (2, 3); } }); } Console.ReadLine (); } If I use TCP binding then maximum 32 connections are opened but if I use HTTP binding, only 2 TCP connections are opened. How can I configure the maximum number of connections that can be opened using HTTP binding?

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• Django: Summing values of records grouped by foreign key

  - by Dan0

  Hi there In django, given the following models (slightly simplified), I'm struggling to work out how I would get a view including sums of groups class Client(models.Model): api_key = models.CharField(unique=True, max_length=250, primary_key=True) name = models.CharField(unique=True, max_length=250) class Purchase(models.Model): purchase_date = models.DateTimeField() client = models.ForeignKey(SavedClient, to_field='api_key') amount_to_invoice = models.FloatField(null=True) For a given month, I'd like to see e.g. April 2010 For Each Client that purchased this month: * CLient: Name * Total amount of Purchases for this month * Total cost of purchases for this month For each Purchase made by client: * Date * Amount * Etc I've been looking into django annotation, but can't get my head around how to sum values of a field for a particular group over a particular month and send the information to a template as a variable/tag. Any info would be appreciated

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• Question with R. Element wise multiplication, addition, and division with 2 data.frames with varying

  - by Michael

  I have a various data.frames with columns of the same length where I am trying to multiple 2 rows together element-wise and then sum this up. For example, below are two vectors I would like to perform this operation with. > a.1[186,] q01_a q01_b q01_c q01_d q01_e q01_f q01_g q01_h q01_i q01_j q01_k q01_l q01_m 3 3 3 3 2 2 2 3 1 NA NA 2 2 and > u.1[186,] q04_avl_a q04_avl_b q04_avl_c q04_avl_d q04_avl_e q04_avl_f q04_avl_g q04_avl_h q04_avl_i q04_avl_j q04_avl_k q04_avl_l q04_avl_m 4 2 3 4 3 4 4 4 3 4 3 3 3` The issue is that various rows have varying numbers of NA's. What I would like to do is skip the multiplication with any missing values ( the 10th and 11th position from my above example), and then after the addition divide by the number of elements that were multiplied (11 from the above example). Most rows are complete and would just be multiplied by 13. Thank you!

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• _mask and Rails

  - by Eric Koslow

  So I am trying to get the cancan gem to work with my rails 3 app and I've hit a problem. I tried to copy the code that Ryan Bates (the creator of the gem) used in his screen cast, but I get an error saying that roles_mask is not a method. I figure that the _mask method was removed from Ruby/Rails at some point, and I'm now wondering what is the replacement. Here's the code in my user.rb model: named_scope :with_role, lambda { |role| {:conditions => "roles_mask & #{2**ROLES.index(role.to_s)} > 0 "} } ROLES = %w[admin student principal admissions] def roles=(roles) self.roles_mask = (roles & ROLES).map { |r| 2**ROLES.index(r) }.sum end def roles ROLES.reject { |r| ((roles_mask || 0) & 2**ROLES.index(r)).zero? } end def role? roles.include? role.to_s end def role_symbols roles.map(&:to_sym) end I'm using Rails 3 and Ruby 1.9.2dev Thank you

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• How to make DD-WRT router's (configured like a repeater) devices be accessible on LAN? (i.e. integrate DHCP for both routers)

  - by Annonomus Penguin

  I have a D-Link DIR-600-A1 router running DD-WRT (using the 601's firmware: except for the model number, they are near identical). It has an Atheros chip, so there is no "repeater" option. You can bypass this by setting the main radio as a client to the main router, and adding a virtual radio configured as an AP. You can then set up the credentials for connecting to the main router and allowing devices to connect to the repeater/router. I have a few devices on my network: Ethernet computers Server with Samba running WiFi devices connected to the main router I then wanted to add a repeater. I have a couple of other things on the repeater: WiFi Computer Other WiFi devices. Anyway, I wanted to connect my WiFi computer to the share on my server via Samba. However, for some reason, my router treats the main router as WAN, not another device. I've tried disabling the SPI firewall: However, that doesn't work. I've tried pinging my WiFi computer from my server. However, I can ping my server from my WiFi computer. AFAIK, they are on the same subset, just using different IPs: the main one uses 192.168.0.x and the repeater uses 192.168.1.x (starting at 100 for some reason). It seems as I need to configure my router(s) to work together for DHCP. I noticed there was a "DHCP forwarder" option, but I have no idea what that would do. A quick note: for some reason (that's beyond me) my ISP disabled the capability to bridge a WiFi to ethernet connection with the router they provide (something about PPPoE or similar...). The service rep I talked to when I was having issues after I changed ISPs said that, but they couldn't explain exactly what they were "blocking." How can I get DD-WRT to not treat the client connection as WAN and the router to recognize the devices connected to the repeater?

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• Drobo FS vs. MacBook Pro: Finder works, Drobo Dashboard doesn't

  - by dash-tom-bang

  Does anyone have any experience with the new Drobo FS, specifically using it from a MacBook Pro? My experience thus far is this: Set up the Drobo Dashboard software (hereinafter called simply 'Dashboard') on my WinXP machine, which is hard-wired to the network to do the data migration from my NAS-that's-being-replaced (a 250G SimpleShare which works well enough but I was always afraid of losing the one disk). The Dashboard seems to work ok, except that the DroboCopy function doesn't work at all. This is the backup solution, which I can configure, and if I launch it (e.g. to back up from the old NAS to the Drobo) it spins the NAS, seeking the drive all over hell and creation, until finally giving up an hour+ later with zero files copied. Selecting only a subset of the data yields the same effect albeit more quickly. On my Mac I installed the Dashboard software too, since most of my fiddling with the device will be from my couch in the living room. Finder connects to the box just fine, fwiw, but Dashboard just sits there, "waiting for connection." This is considerably more bothersome than the above paragraph, but I figured I'd give whatever information I have. Drobo is insisting that I send them this "Debug Log" file that their software generates. Does anyone know what's in it? It's encrypted and they won't tell me, which spooks me just a bit; not like I'm terribly concerned about privacy but I don't want to be sending personal information out to every clown who says they "need" it in order to help me. thanks a ton, -tom!

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• crystal report problem

  - by Baharanji

  Dear all, I have a Table which Contains items and its prices and those prices some in Dollars and the rest in pounds and the items are divided into sections and I want to use a modified Sum function in the Crystal Report so as to show at the end of each group the total in pounds like that in C# int price=0; foreach (item it in items) { if (it.curr=="$") { price+=it.price*DollarPrice } else price+=it.price; } return price; That's exactly what i want to do in crystal reports but i dont have any clue how to do so So if you have any Idea please help me, Regards, Baher.

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• Replacing latex with unicode symbols

  - by Elazar Leibovich

  Often, during a conversation or an email, or at a forum, I would like to type some math, but I don't need full equation support. Unicode symbols should suffice. What I need is an easy way to type math related unicode symbols. Since I already know latex, it makes sense to use the latex symbol mnemonics to type the math symbols. What I currently did is to write an AutoHotKey script which automatically replaces \latexSymbol with the corresponding unicode symbol, using the "hotstrings" AutoHotKey feautres. However, the AutoHotKey hotstrings proved unstable for many strings. Having a couple of tens lines would cause AHK to fail recognizing the strings from time to time. Any other solution? (No, Alt+unicode number isn't convenient enough) Attached is my AHK script. The PutUni function is taken from here. ::\infty:: PutUni("e2889e") return ::\sum:: PutUni("e28891") return ::\int:: PutUni("e288ab") return ::\pm:: PutUni("c2b1") return ::\alpha:: PutUni("c991") return ::\beta:: PutUni("c992") return ::\phi:: PutUni("c9b8") return ::\delta:: PutUni("ceb4") return ::\pi:: PutUni("cf80") return ::\omega:: PutUni("cf89") return ::\in:: PutUni("e28888") return ::\notin:: PutUni("e28889") return ::\iff:: PutUni("e28794") return ::\leq:: PutUni("e289a4") return ::\geq:: PutUni("e289a5") return ::\sqrt:: PutUni("e2889a") return ::\neq:: PutUni("e289a0") return ::\subset:: PutUni("e28a82") return ::\nsubset:: PutUni("e28a84") return ::\nsubseteq:: PutUni("e28a88") return ::\subseteq:: PutUni("e28a86") return ::\prod:: PutUni("e2888f") return ::\N:: PutUni("e28495") return

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• how to group by over anonymous type with vb.net linq to object

  - by smoothdeveloper

  I'm trying to write a linq to object query in vb.net, here is the c# version of what I'm trying to achieve (I'm running this in linqpad): void Main() { var items = GetArray( new {a="a",b="a",c=1} , new {a="a",b="a",c=2} , new {a="a",b="b",c=1} ); ( from i in items group i by new {i.a, i.b} into g let p = new{ k = g, v = g.Sum((i)=>i.c)} where p.v > 1 select p ).Dump(); } // because vb.net doesn't support anonymous type array initializer, it will ease the translation T[] GetArray<T>(params T[] values){ return values; } I'm having hard time with either the group by syntax which is not the same (vb require 'identifier = expression' at some places, as well as with the summing functor with 'expression required' ) Thanks so much for your help!

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• external postfix forwarding to zimbra server

  - by Marko

  I want to migrate from my current mail server (old_server) for my domain mydomain.com. old_server setup is Postfix+LDAP+Cyrus. Now I want to migrate my domain mail to Zimbra server (zimbra), but I am considering option to leave current mail server working in the first phase, and then to only have subset of email addresses to be forwarded to zimbra server. It seems that zimbra refers this in their documentation as 'edge MTA'. Current config mydomain.com MX: old_server <---------- smtp send ----------> smtp receive New config mydomain.com MX: old_server zimbra <------------------------------------------- smtp send ----------> smtp receive ---- forward ----> smtp receive I need following: old_server to receive mail for my domain as before, but for some of the email addresses I want them to be delivered to zimbra server. I should be able to determine which email addresses will be forwarded. I would like to avoid possible false spam detections for mails from mydomain.com due to this setup. Questions: How should I configure postfix on old_server to support this mail forwarding? To avoid false spam detection, can I have outgoing mail from mydomain.com to be sent by zimbra or should I use old_server? Is there anything extra I would need to do in order to avoid possibility of my outgoing mails being marked as spam on other servers?

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