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  • SQL Server crashes when remote query fails

    - by Hemanshu Bhojak
    Setup: I have a linked server setup on SQL Server 2005 which is pointing to an Oracle DB. The linked server has RPC enabled. Problem: When a query throws an exception on the remote server (Oracle DB) the SQL Server instance crashes. The logs say that the crash was due to some problem with the RPC call. Is there a way in which I can prevent the entire server to collapse but also use RPC over my linked server. EDIT: Event Log SQL Server is terminating because of fatal exception c0000005. This error may be caused by an unhandled Win32 or C++ exception, or by an access violation encountered during exception handling. Check the SQL error log for any related stack dumps or messages. This exception forces SQL Server to shutdown. To recover from this error, restart the server (unless SQLAgent is configured to auto restart). For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

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  • SQL Server crashes when remote query fails

    - by Hemanshu Bhojak
    Setup: I have a linked server setup on SQL Server 2005 which is pointing to an Oracle DB. The linked server has RPC enabled. Problem: When a query throws an exception on the remote server (Oracle DB) the SQL Server instance crashes. The logs say that the crash was due to some problem with the RPC call. Is there a way in which I can prevent the entire server to collapse but also use RPC over my linked server. EDIT: Event Log SQL Server is terminating because of fatal exception c0000005. This error may be caused by an unhandled Win32 or C++ exception, or by an access violation encountered during exception handling. Check the SQL error log for any related stack dumps or messages. This exception forces SQL Server to shutdown. To recover from this error, restart the server (unless SQLAgent is configured to auto restart). For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

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  • SQL Server 2008 Hardware Recommendation;

    - by Jay
    Hi,I work for a large fortune 500 company. We have several SQL 2005 Servers running on DELL Poweredge 2950 with 8 GB RAM and 4 CPU's. Storage is DMX RAID 10. We are in the process of migrating to sql 2008. We are planning on consolidating multiple sql 2005 into single SQL 2008 Server.If anyone can suggest hardware I would appreciate. We have looked at DELL R710, I was wondering if there are other servers that are good for running SQL 2008. Thanks

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  • Unable to connect to local SQL Express (2008)

    - by Will
    I'm trying to get an installation of SQL Express 2008 working, but no matter what I do I can't connect to it with management studio. I've enabled TCP/IP for the instance. I've tried connecting with machinename\instance, .\instance, (local), etc etc etc. Nothing works, and I always get the same message. If I browse for a server, the only server listed is the local integration services, which I can connect to just fine. The SQL server service is running (SQLEXPRESS), SQL Server Agent is not (and won't, can't enable it), and SQL Server Browser is. Anyone have any suggestions on where to go next? I've tried uninstalling EVERYTHING sql and reinstalling, no change.

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  • Activity monitor is unable to execute queries against server

    - by mika
    SQL Server Activity Monitor fails with an error dialog: TITLE: Microsoft SQL Server Management Studio The Activity Monitor is unable to execute queries against server [SERVER]. Activity Monitor for this instance will be placed into a paused state. Use the context menu in the overview pane to resume the Activity Monitor. ADDITIONAL INFORMATION: Unable to find SQL Server process ID [PID] on server [SERVER] (Microsoft.SqlServer.Management.ResourceMonitoring) I have this problem on SQL Server 2008 R2 x64 Developer Edition, but I think it is found in all 64bit systems using SQL Server 2008, under some yet unidentified conditions. There is a bug report on this in Microsoft Connect. It seems that the problem is not solved yet.

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  • Renaming server - sql 2008 server instance affected

    - by user986363
    Will changing the computer name on which SQL Server 2008 is installed on affect SQL Server in anyway? Or will changing the computer name be transparent to SQL Server? For example: I plan to install Windows 2008 Server and naming it "BobStage". Next I will install SQL Server 2008 R2 and restore a few DB's. Finally I plan to rename the windows machine to "BobLive". Will me renaming the computer's name affect SQL Server's instance ID/name and possibly break something?

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  • SQL Server agent died

    - by Manjot
    3 SQL server agents stopped and didn't restart automatically untill we manually restarted them. SQL servers are on SQL 2005 X86 standard edition. The error message that was reported in Application log was: Faulting application sqlagent90.exe, version 2005.90.4211.0, stamp 49837478, faulting module kernel32.dll, version 5.2.3790.4480, stamp 49c51f0a, debug? 0, fault address 0x0000bef7. No errors were reported in SQL server logs or SQl agent logs. Does anyone know what this means? I tried to Google but no luck. Thanks in advance!

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  • Accessing SQL Server in Windows XP Mode Virtual Pc

    - by DavidStein
    I have a laptop running 64bit Windows 7 Ultimate. I created a Virtual PC using Microsoft XP Mode. I've installed SQL Server 2000 on the Virtual Machine. I have SQL Server 2008 R2 installed on the Windows 7 machine (laptop). I can browse to the SQL 2000 instance (it sees it), but I cannot successfully connect using either Windows or SQL Server Authentication. I don't get an error, the attempt just times out. I have the Windows XP Mode Firewall turned off, and there doesn't appear to be anything in the Event logs either. Any ideas how I can query the XP Mode SQL Server from the Windows 7 machine?

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  • Execution plan different on two different Sql Servers

    - by Lieven Cardoen
    On our sql server, a query takes 20 ms. If I look at the execution plan, parallelism is used, hash match, Bitmap create, ... a lot of images with two arrows pointing to the left. On sql server of a customer where our product runs, the same query takes 2500 ms. If I look at their execution plan, no parallelism or any of the things with arrows are used... I've been searching for a couple of days no why the query runs so much slower on their sql server. Is parallelism and all of the other things something that can be configured on their sql server? And how to you configure that? What are the dangers of using parallelism? Another strange thing is that on our server, the query needs some 1200 reads and 0 writes. On their sql server it needs 1.5 million reads and some 1500 writes. Why these writes when a read query is done?

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  • Troubleshooting a high SQL Server Compilation/Batch-Ratio

    - by Sleepless
    I have a SQL Server (quad core x86, 4GB RAM) that constantly has almost the same values for "SQLServer:SQL Statistics: SQL compilations/sec" and "SQLServer:SQL Statistics: SQL batches/sec". This could be interpreted as a server running 100% ad hoc queries, each one of which has to be recompiled, but this is not the case here. The sys.dm_exec_query_stats DMV lists hundreds of query plans with an execution_count much larger than 1. Does anybody have any idea how to interpret / troubleshoot this phenomenon? BTW, the server's general performance counters (CPU,I/O,RAM) all show very modest utilization.

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  • Only allow certain processes to connect to MS SQL

    - by Fred
    I've lost the source code for a very old application that connects to a MS SQL-server for some SQL queries. Since the login is hard-coded in the application I can't change the username/password on the server. One day the password will probably be known to the users and we surely need to change it. But how? One idea is to only allow the old application to do the queries on the SQL server and block out any other application like the query analyzer etc. Can I set process permission somehow? The SQL server (MS SQL 2005) and application (C++) are on the same machine It's too costly to rewrite the old program Thanks for help!

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  • Recommended service account setup for MS SQL Server 2005/2008

    - by boxerbucks
    We have a number of MS SQL servers in our environment running either SQL Server 2005 standard/enterprise or SQL server 2008 enterprise. Currently the SQL services are running as local service or network service and the MS recommended best practice is to run as a domain account which is what we are trying to move towards. Is the best practice with regards to domain accounts to have a separate domain account per service per server? So if we have 4 SQL services we want to run per server and we have 50 servers, we would create 50 * 4 = 200 accounts in AD? This seems excessive to me and I was wondering if anyone has any real experience with this type of setup and it's management.

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  • SQL SERVER AGENT CAN NOT START

    - by Keith Ph?m
    http://imageshack.us/photo/my-images/819/sqlserveragent3.png/ http://imageshack.us/photo/my-images/341/sqlserveragent.png/ I still can not start SQL server agent . When Sql server agent just starts and stop immedietly .I don't know what's happening in the middle .. I already login by the Network Service account in configuration tools and assign member role in msmb database for SQL Server agent. Pls give me an advice I use win 7 ultimate , sql server 2008: Microsoft SQL Server Management Studio 10.0.1600.22 ((SQL_PreRelease).080709-1414 ) Microsoft Data Access Components (MDAC) 6.1.7600.16385 (win7_rtm.090713-1255) Microsoft MSXML 3.0 4.0 5.0 6.0 Microsoft Internet Explorer 9.0.8112.16421 Microsoft .NET Framework 2.0.50727.4971 Operating System 6.1.7600 Thanks

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  • Cannot authenticate a domain user with SQL Server 2008

    - by Sambo
    I'm new to setting up Domains so I might be missing something simple here... I've installed SQL Server 2008 on a Windows Server 2008 R2 box and I have another WS2008 R2 box acting as the domain controller. I've joined the SQL server to the domain and it seems to be behaving itself fine. I can ping the DC by name and IP address. I created a domain user 'SPSQLAdmin' that I want to use for database access with SharePoint but I can't seem to log on to SQL with this user. SQL complains, saying that the user belongs to an untrusted domain. I've configured the DC to delegate control for any service to the SQL Server but it doesn't improve the situation. What should I try next? Thanks in advance.

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  • SQL server environment

    - by Olegas D
    Hello I'm considering a bit of changes in current sales environment. And trying to check all cons and pros. Current situation. SQL server (quite decent HP server - server1) + backup server (smaller Dell server - server2). all sql files and sql server itself are on the server1. If something goes wrong with server1 I will have to manually move to server2. Connecting to the sql server: 1 HQ (where server located) + 4 sites through VPN. Now I'm considering 2 scenarios: Buy some storage system + update existing servers (add ram, upgrade processors) and go for VMWare ESXI. Rent a server at a datacenter + rent virtual server in case real server goes down. Also rent some space at data storage to keep SQL files there. Have anyone considered these things and maybe found some good pros/cons list? ;) Thanks

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  • Error when I try to connect to a SQL Server 2005 from the internet

    - by Manish
    My SQL Server is on a local machine. I want to access it through internet. I created a website through I want to connect local SQL Server 2005. This is the error message: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified) Thanks for a reply!

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  • Does SQL Server Management Studio 2008 Activity Monitor work with SQL Server 2000?

    - by Andrew Janke
    I am trying to use SQL Server Management Studio 2008's Activity Monitor with an SQL Server 2000 instance to diagnose some query performance issues. I can connect SMSS 2008 to the db fine, and use it to browse objects and run queries. But when I press the Activity Monitor button, it pops up an error message saying: Microsoft SQL Server Management Studio This operation does not support connections to Microsoft SQL Server Personal Edition version 8.00.818. This MSDN article implies that Activity Monitor works with SQL Server 2000. Is it the fact that it's Personal Edition that's preventing it from working? The error message isn't clear whether it's the edition or version that's the problem.

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  • SQL Server Licensing

    - by John
    We are looking at moving our fractured code base that uses MySQL in some places and SQL Server in other places. I'm suggesting that for our purposes we don't need anything that MySQL can't do. The argument is that we have to have SQL Server anyway because we have Exchange and SharePoint. I always thought that SQL Server didn't require a separate license when using Exchange or SharePoint (WSS version). We are also using TFS. If there is a server product from Microsoft which requires the use of SQL Server then doesn't it come with some form of licensing for SQL Server? Can anyone lend some insight to this? Thanks!

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  • Remote connection issue with Sql Server 2005 with SMS and Services but not IIS

    - by Mallioch
    Here is the situation: I have a Server 2008 box that is trying to connect to a Sql Server 2005 instance. Connections from websites running in the context of IIS work fine to the Sql Server machine using Sql Server authentication. Rockin'. However, using the same connection string, I cannot get a windows service on the same box to communicate with the Sql Server. Nor can I get management studio to connect from the same box. IIS great, other options no so much. For grins I have tried monkeying with the user accounts in the IIS app pools to match that of the service to get the sites to break and that hasn't worked, so it doesn't appear to be a user account issue. Since this is happening with two different programs and not with IIS, I'm assuming there is something shut down on the Sql Server that needs to allow non-IIS connecting things to communicate, but I have no idea what that would be. Any help would be appreciated.

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  • Shadow volume shader optimization (GLSL)

    - by Soubok
    I wondering if there is a way to optimize this vertex shader. This vertex shader projects (in the light direction) a vertex to the far plane if it is in the shadow. void main(void) { vec3 lightDir = (gl_ModelViewMatrix * gl_Vertex - gl_LightSource[0].position).xyz; // if the vertex is lit if ( dot(lightDir, gl_NormalMatrix * gl_Normal) < 0.01 ) { // don't move it gl_Position = ftransform(); } else { // move it far, is the light direction vec4 fin = gl_ProjectionMatrix * ( gl_ModelViewMatrix * gl_Vertex + vec4(normalize(lightDir) * 100000.0, 0.0) ); if ( fin.z > fin.w ) // if fin is behind the far plane fin.z = fin.w; // move to the far plane (needed for z-fail algo.) gl_Position = fin; } }

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  • MySql query optimization help

    - by rohitgu
    I have few queries and am not able to figure out how to optimize them, QUERY 1 select * from t_twitter_tracking where classified is null and tweetType='ENGLISH' order by id limit 500; QUERY 2 Select count(*) as cnt, DATE_FORMAT(CONVERT_TZ(wrdTrk.createdOnGMTDate,'+00:00','+05:30'),'%Y-%m-%d') as dat from t_twitter_tracking wrdTrk where wrdTrk.word like ('dell') and CONVERT_TZ(wrdTrk.createdOnGMTDate,'+00:00','+05:30') between '2010-12-12 00:00:00' and '2010-12-26 00:00:00' group by dat; Both these queries run on the same table, CREATE TABLE `t_twitter_tracking` ( `id` BIGINT(20) NOT NULL AUTO_INCREMENT, `word` VARCHAR(200) NOT NULL, `tweetId` BIGINT(100) NOT NULL, `twtText` VARCHAR(800) NULL DEFAULT NULL, `language` TEXT NULL, `links` TEXT NULL, `tweetType` VARCHAR(20) NULL DEFAULT NULL, `source` TEXT NULL, `sourceStripped` TEXT NULL, `isTruncated` VARCHAR(40) NULL DEFAULT NULL, `inReplyToStatusId` BIGINT(30) NULL DEFAULT NULL, `inReplyToUserId` INT(11) NULL DEFAULT NULL, `rtUsrProfilePicUrl` TEXT NULL, `isFavorited` VARCHAR(40) NULL DEFAULT NULL, `inReplyToScreenName` VARCHAR(40) NULL DEFAULT NULL, `latitude` BIGINT(100) NOT NULL, `longitude` BIGINT(100) NOT NULL, `retweetedStatus` VARCHAR(40) NULL DEFAULT NULL, `statusInReplyToStatusId` BIGINT(100) NOT NULL, `statusInReplyToUserId` BIGINT(100) NOT NULL, `statusFavorited` VARCHAR(40) NULL DEFAULT NULL, `statusInReplyToScreenName` TEXT NULL, `screenName` TEXT NULL, `profilePicUrl` TEXT NULL, `twitterId` BIGINT(100) NOT NULL, `name` TEXT NULL, `location` VARCHAR(100) NULL DEFAULT NULL, `bio` TEXT NULL, `url` TEXT NULL COLLATE 'latin1_swedish_ci', `utcOffset` INT(11) NULL DEFAULT NULL, `timeZone` VARCHAR(100) NULL DEFAULT NULL, `frenCnt` BIGINT(20) NULL DEFAULT '0', `createdAt` DATETIME NULL DEFAULT NULL, `createdOnGMT` VARCHAR(40) NULL DEFAULT NULL, `createdOnServerTime` DATETIME NULL DEFAULT NULL, `follCnt` BIGINT(20) NULL DEFAULT '0', `favCnt` BIGINT(20) NULL DEFAULT '0', `totStatusCnt` BIGINT(20) NULL DEFAULT NULL, `usrCrtDate` VARCHAR(200) NULL DEFAULT NULL, `humanSentiment` VARCHAR(30) NULL DEFAULT NULL, `replied` BIT(1) NULL DEFAULT NULL, `replyMsg` TEXT NULL, `classified` INT(32) NULL DEFAULT NULL, `createdOnGMTDate` DATETIME NULL DEFAULT NULL, `locationDetail` TEXT NULL, `geonameid` INT(11) NULL DEFAULT NULL, `country` VARCHAR(255) NULL DEFAULT NULL, `continent` CHAR(2) NULL DEFAULT NULL, `placeLongitude` FLOAT NULL DEFAULT NULL, `placeLatitude` FLOAT NULL DEFAULT NULL, PRIMARY KEY (`id`), INDEX `id` (`id`, `word`), INDEX `createdOnGMT_index` (`createdOnGMT`) USING BTREE, INDEX `word_index` (`word`) USING BTREE, INDEX `location_index` (`location`) USING BTREE, INDEX `classified_index` (`classified`) USING BTREE, INDEX `tweetType_index` (`tweetType`) USING BTREE, INDEX `getunclassified_index` (`classified`, `tweetType`) USING BTREE, INDEX `timeline_index` (`word`, `createdOnGMTDate`, `classified`) USING BTREE, INDEX `createdOnGMTDate_index` (`createdOnGMTDate`) USING BTREE, INDEX `locdetail_index` (`country`, `id`) USING BTREE, FULLTEXT INDEX `twtText_index` (`twtText`) ) COLLATE='utf8_general_ci' ENGINE=MyISAM ROW_FORMAT=DEFAULT AUTO_INCREMENT=12608048; The table has more than 10 million records. How can I optimize it?

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  • sql: Group by x,y,z; return grouped by x,y with lowest f(z)

    - by Sai Emrys
    This is for http://cssfingerprint.com I collect timing stats about how fast the different methods I use perform on different browsers, etc., so that I can optimize the scraping speed. Separately, I have a report about what each method returns for a handful of URLs with known-correct values, so that I can tell which methods are bogus on which browsers. (Each is different, alas.) The related tables look like this: CREATE TABLE `browser_tests` ( `id` int(11) NOT NULL AUTO_INCREMENT, `bogus` tinyint(1) DEFAULT NULL, `result` tinyint(1) DEFAULT NULL, `method` varchar(255) DEFAULT NULL, `url` varchar(255) DEFAULT NULL, `os` varchar(255) DEFAULT NULL, `browser` varchar(255) DEFAULT NULL, `version` varchar(255) DEFAULT NULL, `created_at` datetime DEFAULT NULL, `updated_at` datetime DEFAULT NULL, `user_agent` varchar(255) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=33784 DEFAULT CHARSET=latin1 CREATE TABLE `method_timings` ( `id` int(11) NOT NULL AUTO_INCREMENT, `method` varchar(255) DEFAULT NULL, `batch_size` int(11) DEFAULT NULL, `timing` int(11) DEFAULT NULL, `os` varchar(255) DEFAULT NULL, `browser` varchar(255) DEFAULT NULL, `version` varchar(255) DEFAULT NULL, `user_agent` varchar(255) DEFAULT NULL, `created_at` datetime DEFAULT NULL, `updated_at` datetime DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=28849 DEFAULT CHARSET=latin1 (user_agent is broken down pre-insert into browser, version, and os from a small list of recognized values using regex; I keep the original user-agent string just in case.) I have a query like this that tells me the average timing for every non-bogus browser / version / method tuple: select c, avg(bogus) as bog, timing, method, browser, version from browser_tests as b inner join ( select count(*) as c, round(avg(timing)) as timing, method, browser, version from method_timings group by browser, version, method having c > 10 order by browser, version, timing ) as t using (browser, version, method) group by browser, version, method having bog < 1 order by browser, version, timing; Which returns something like: c bog tim method browser version 88 0.8333 184 reuse_insert Chrome 4.0.249.89 18 0.0000 238 mass_insert_width Chrome 4.0.249.89 70 0.0400 246 mass_insert Chrome 4.0.249.89 70 0.0400 327 mass_noinsert Chrome 4.0.249.89 88 0.0556 367 reuse_reinsert Chrome 4.0.249.89 88 0.0556 383 jquery Chrome 4.0.249.89 88 0.0556 863 full_reinsert Chrome 4.0.249.89 187 0.0000 105 jquery Chrome 5.0.307.11 187 0.8806 109 reuse_insert Chrome 5.0.307.11 123 0.0000 110 mass_insert_width Chrome 5.0.307.11 176 0.0000 231 mass_noinsert Chrome 5.0.307.11 176 0.0000 237 mass_insert Chrome 5.0.307.11 187 0.0000 314 reuse_reinsert Chrome 5.0.307.11 187 0.0000 372 full_reinsert Chrome 5.0.307.11 12 0.7500 82 reuse_insert Chrome 5.0.335.0 12 0.2500 102 jquery Chrome 5.0.335.0 [...] I want to modify this query to return only the browser/version/method with the lowest timing - i.e. something like: 88 0.8333 184 reuse_insert Chrome 4.0.249.89 187 0.0000 105 jquery Chrome 5.0.307.11 12 0.7500 82 reuse_insert Chrome 5.0.335.0 [...] How can I do this, while still returning the method that goes with that lowest timing? I could filter it app-side, but I'd rather do this in mysql since it'd work better with my caching.

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  • Java code optimization on matrix windowing computes in more time

    - by rano
    I have a matrix which represents an image and I need to cycle over each pixel and for each one of those I have to compute the sum of all its neighbors, ie the pixels that belong to a window of radius rad centered on the pixel. I came up with three alternatives: The simplest way, the one that recomputes the window for each pixel The more optimized way that uses a queue to store the sums of the window columns and cycling through the columns of the matrix updates this queue by adding a new element and removing the oldes The even more optimized way that does not need to recompute the queue for each row but incrementally adjusts a previously saved one I implemented them in c++ using a queue for the second method and a combination of deques for the third (I need to iterate through their elements without destructing them) and scored their times to see if there was an actual improvement. it appears that the third method is indeed faster. Then I tried to port the code to Java (and I must admit that I'm not very comfortable with it). I used ArrayDeque for the second method and LinkedLists for the third resulting in the third being inefficient in time. Here is the simplest method in C++ (I'm not posting the java version since it is almost identical): void normalWindowing(int mat[][MAX], int cols, int rows, int rad){ int i, j; int h = 0; for (i = 0; i < rows; ++i) { for (j = 0; j < cols; j++) { h = 0; for (int ry =- rad; ry <= rad; ry++) { int y = i + ry; if (y >= 0 && y < rows) { for (int rx =- rad; rx <= rad; rx++) { int x = j + rx; if (x >= 0 && x < cols) { h += mat[y][x]; } } } } } } } Here is the second method (the one optimized through columns) in C++: void opt1Windowing(int mat[][MAX], int cols, int rows, int rad){ int i, j, h, y, col; queue<int>* q = NULL; for (i = 0; i < rows; ++i) { if (q != NULL) delete(q); q = new queue<int>(); h = 0; for (int rx = 0; rx <= rad; rx++) { if (rx < cols) { int mem = 0; for (int ry =- rad; ry <= rad; ry++) { y = i + ry; if (y >= 0 && y < rows) { mem += mat[y][rx]; } } q->push(mem); h += mem; } } for (j = 1; j < cols; j++) { col = j + rad; if (j - rad > 0) { h -= q->front(); q->pop(); } if (j + rad < cols) { int mem = 0; for (int ry =- rad; ry <= rad; ry++) { y = i + ry; if (y >= 0 && y < rows) { mem += mat[y][col]; } } q->push(mem); h += mem; } } } } And here is the Java version: public static void opt1Windowing(int [][] mat, int rad){ int i, j = 0, h, y, col; int cols = mat[0].length; int rows = mat.length; ArrayDeque<Integer> q = null; for (i = 0; i < rows; ++i) { q = new ArrayDeque<Integer>(); h = 0; for (int rx = 0; rx <= rad; rx++) { if (rx < cols) { int mem = 0; for (int ry =- rad; ry <= rad; ry++) { y = i + ry; if (y >= 0 && y < rows) { mem += mat[y][rx]; } } q.addLast(mem); h += mem; } } j = 0; for (j = 1; j < cols; j++) { col = j + rad; if (j - rad > 0) { h -= q.peekFirst(); q.pop(); } if (j + rad < cols) { int mem = 0; for (int ry =- rad; ry <= rad; ry++) { y = i + ry; if (y >= 0 && y < rows) { mem += mat[y][col]; } } q.addLast(mem); h += mem; } } } } I recognize this post will be a wall of text. Here is the third method in C++: void opt2Windowing(int mat[][MAX], int cols, int rows, int rad){ int i = 0; int j = 0; int h = 0; int hh = 0; deque< deque<int> *> * M = new deque< deque<int> *>(); for (int ry = 0; ry <= rad; ry++) { if (ry < rows) { deque<int> * q = new deque<int>(); M->push_back(q); for (int rx = 0; rx <= rad; rx++) { if (rx < cols) { int val = mat[ry][rx]; q->push_back(val); h += val; } } } } deque<int> * C = new deque<int>(M->front()->size()); deque<int> * Q = new deque<int>(M->front()->size()); deque<int> * R = new deque<int>(M->size()); deque< deque<int> *>::iterator mit; deque< deque<int> *>::iterator mstart = M->begin(); deque< deque<int> *>::iterator mend = M->end(); deque<int>::iterator rit; deque<int>::iterator rstart = R->begin(); deque<int>::iterator rend = R->end(); deque<int>::iterator cit; deque<int>::iterator cstart = C->begin(); deque<int>::iterator cend = C->end(); for (mit = mstart, rit = rstart; mit != mend, rit != rend; ++mit, ++rit) { deque<int>::iterator pit; deque<int>::iterator pstart = (* mit)->begin(); deque<int>::iterator pend = (* mit)->end(); for(cit = cstart, pit = pstart; cit != cend && pit != pend; ++cit, ++pit) { (* cit) += (* pit); (* rit) += (* pit); } } for (i = 0; i < rows; ++i) { j = 0; if (i - rad > 0) { deque<int>::iterator cit; deque<int>::iterator cstart = C->begin(); deque<int>::iterator cend = C->end(); deque<int>::iterator pit; deque<int>::iterator pstart = (M->front())->begin(); deque<int>::iterator pend = (M->front())->end(); for(cit = cstart, pit = pstart; cit != cend; ++cit, ++pit) { (* cit) -= (* pit); } deque<int> * k = M->front(); M->pop_front(); delete k; h -= R->front(); R->pop_front(); } int row = i + rad; if (row < rows && i > 0) { deque<int> * newQ = new deque<int>(); M->push_back(newQ); deque<int>::iterator cit; deque<int>::iterator cstart = C->begin(); deque<int>::iterator cend = C->end(); int rx; int tot = 0; for (rx = 0, cit = cstart; rx <= rad; rx++, ++cit) { if (rx < cols) { int val = mat[row][rx]; newQ->push_back(val); (* cit) += val; tot += val; } } R->push_back(tot); h += tot; } hh = h; copy(C->begin(), C->end(), Q->begin()); for (j = 1; j < cols; j++) { int col = j + rad; if (j - rad > 0) { hh -= Q->front(); Q->pop_front(); } if (j + rad < cols) { int val = 0; for (int ry =- rad; ry <= rad; ry++) { int y = i + ry; if (y >= 0 && y < rows) { val += mat[y][col]; } } hh += val; Q->push_back(val); } } } } And finally its Java version: public static void opt2Windowing(int [][] mat, int rad){ int cols = mat[0].length; int rows = mat.length; int i = 0; int j = 0; int h = 0; int hh = 0; LinkedList<LinkedList<Integer>> M = new LinkedList<LinkedList<Integer>>(); for (int ry = 0; ry <= rad; ry++) { if (ry < rows) { LinkedList<Integer> q = new LinkedList<Integer>(); M.addLast(q); for (int rx = 0; rx <= rad; rx++) { if (rx < cols) { int val = mat[ry][rx]; q.addLast(val); h += val; } } } } int firstSize = M.getFirst().size(); int mSize = M.size(); LinkedList<Integer> C = new LinkedList<Integer>(); LinkedList<Integer> Q = null; LinkedList<Integer> R = new LinkedList<Integer>(); for (int k = 0; k < firstSize; k++) { C.add(0); } for (int k = 0; k < mSize; k++) { R.add(0); } ListIterator<LinkedList<Integer>> mit; ListIterator<Integer> rit; ListIterator<Integer> cit; ListIterator<Integer> pit; for (mit = M.listIterator(), rit = R.listIterator(); mit.hasNext();) { Integer r = rit.next(); int rsum = 0; for (cit = C.listIterator(), pit = (mit.next()).listIterator(); cit.hasNext();) { Integer c = cit.next(); Integer p = pit.next(); rsum += p; cit.set(c + p); } rit.set(r + rsum); } for (i = 0; i < rows; ++i) { j = 0; if (i - rad > 0) { for(cit = C.listIterator(), pit = M.getFirst().listIterator(); cit.hasNext();) { Integer c = cit.next(); Integer p = pit.next(); cit.set(c - p); } M.removeFirst(); h -= R.getFirst(); R.removeFirst(); } int row = i + rad; if (row < rows && i > 0) { LinkedList<Integer> newQ = new LinkedList<Integer>(); M.addLast(newQ); int rx; int tot = 0; for (rx = 0, cit = C.listIterator(); rx <= rad; rx++) { if (rx < cols) { Integer c = cit.next(); int val = mat[row][rx]; newQ.addLast(val); cit.set(c + val); tot += val; } } R.addLast(tot); h += tot; } hh = h; Q = new LinkedList<Integer>(); Q.addAll(C); for (j = 1; j < cols; j++) { int col = j + rad; if (j - rad > 0) { hh -= Q.getFirst(); Q.pop(); } if (j + rad < cols) { int val = 0; for (int ry =- rad; ry <= rad; ry++) { int y = i + ry; if (y >= 0 && y < rows) { val += mat[y][col]; } } hh += val; Q.addLast(val); } } } } I guess that most is due to the poor choice of the LinkedList in Java and to the lack of an efficient (not shallow) copy method between two LinkedList. How can I improve the third Java method? Am I doing some conceptual error? As always, any criticisms is welcome. UPDATE Even if it does not solve the issue, using ArrayLists, as being suggested, instead of LinkedList improves the third method. The second one performs still better (but when the number of rows and columns of the matrix is lower than 300 and the window radius is small the first unoptimized method is the fastest in Java)

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  • Matlab: Optimization by perturbing variable

    - by S_H
    My main script contains following code: %# Grid and model parameters nModel=50; nModel_want=1; nI_grid1=5; Nth=1; nRow.Scale1=5; nCol.Scale1=5; nRow.Scale2=5^2; nCol.Scale2=5^2; theta = 90; % degrees a_minor = 2; % range along minor direction a_major = 5; % range along major direction sill = var(reshape(Deff_matrix_NthModel,nCell.Scale1,1)); % variance of the coarse data matrix of size nRow.Scale1 X nCol.Scale1 %# Covariance computation % Scale 1 for ihRow = 1:nRow.Scale1 for ihCol = 1:nCol.Scale1 [cov.Scale1(ihRow,ihCol),heff.Scale1(ihRow,ihCol)] = general_CovModel(theta, ihCol, ihRow, a_minor, a_major, sill, 'Exp'); end end % Scale 2 for ihRow = 1:nRow.Scale2 for ihCol = 1:nCol.Scale2 [cov.Scale2(ihRow,ihCol),heff.Scale2(ihRow,ihCol)] = general_CovModel(theta, ihCol/(nCol.Scale2/nCol.Scale1), ihRow/(nRow.Scale2/nRow.Scale1), a_minor, a_major, sill/(nRow.Scale2*nCol.Scale2), 'Exp'); end end %# Scale-up of fine scale values by averaging [covAvg.Scale2,var_covAvg.Scale2,varNorm_covAvg.Scale2] = general_AverageProperty(nRow.Scale2/nRow.Scale1,nCol.Scale2/nCol.Scale1,1,nRow.Scale1,nCol.Scale1,1,cov.Scale2,1); I am using two functions, general_CovModel() and general_AverageProperty(), in my main script which are given as following: function [cov,h_eff] = general_CovModel(theta, hx, hy, a_minor, a_major, sill, mod_type) % mod_type should be in strings angle_rad = theta*(pi/180); % theta in degrees, angle_rad in radians R_theta = [sin(angle_rad) cos(angle_rad); -cos(angle_rad) sin(angle_rad)]; h = [hx; hy]; lambda = a_minor/a_major; D_lambda = [lambda 0; 0 1]; h_2prime = D_lambda*R_theta*h; h_eff = sqrt((h_2prime(1)^2)+(h_2prime(2)^2)); if strcmp(mod_type,'Sph')==1 || strcmp(mod_type,'sph') ==1 if h_eff<=a cov = sill - sill.*(1.5*(h_eff/a_minor)-0.5*((h_eff/a_minor)^3)); else cov = sill; end elseif strcmp(mod_type,'Exp')==1 || strcmp(mod_type,'exp') ==1 cov = sill-(sill.*(1-exp(-(3*h_eff)/a_minor))); elseif strcmp(mod_type,'Gauss')==1 || strcmp(mod_type,'gauss') ==1 cov = sill-(sill.*(1-exp(-((3*h_eff)^2/(a_minor^2))))); end and function [PropertyAvg,variance_PropertyAvg,NormVariance_PropertyAvg]=... general_AverageProperty(blocksize_row,blocksize_col,blocksize_t,... nUpscaledRow,nUpscaledCol,nUpscaledT,PropertyArray,omega) % This function computes average of a property and variance of that averaged % property using power averaging PropertyAvg=zeros(nUpscaledRow,nUpscaledCol,nUpscaledT); %# Average of property for k=1:nUpscaledT, for j=1:nUpscaledCol, for i=1:nUpscaledRow, sum=0; for a=1:blocksize_row, for b=1:blocksize_col, for c=1:blocksize_t, sum=sum+(PropertyArray((i-1)*blocksize_row+a,(j-1)*blocksize_col+b,(k-1)*blocksize_t+c).^omega); % add all the property values in 'blocksize_x','blocksize_y','blocksize_t' to one variable end end end PropertyAvg(i,j,k)=(sum/(blocksize_row*blocksize_col*blocksize_t)).^(1/omega); % take average of the summed property end end end %# Variance of averageed property variance_PropertyAvg=var(reshape(PropertyAvg,... nUpscaledRow*nUpscaledCol*nUpscaledT,1),1,1); %# Normalized variance of averageed property NormVariance_PropertyAvg=variance_PropertyAvg./(var(reshape(... PropertyArray,numel(PropertyArray),1),1,1)); Question: Using Matlab, I would like to optimize covAvg.Scale2 such that it matches closely with cov.Scale1 by perturbing/varying any (or all) of the following variables 1) a_minor 2) a_major 3) theta Thanks.

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  • Compiler optimization of repeated accessor calls

    - by apocalypse9
    I've found recently that for some types of financial calculations that the following pattern is much easier to follow and test especially in situations where we may need to get numbers from various stages of the computation. public class nonsensical_calculator { ... double _rate; int _term; int _days; double monthlyRate { get { return _rate / 12; }} public double days { get { return (1 - i); }} double ar { get { return (1+ days) /(monthlyRate * days) double bleh { get { return Math.Pow(ar - days, _term) public double raar { get { return bleh * ar/2 * ar / days; }} .... } Obviously this often results in multiple calls to the same accessor within a given formula. I was curious as to whether or not the compiler is smart enough to optimize away these repeated calls with no intervening change in state, or whether this style is causing a decent performance hit. Further reading suggestions are always appreciated

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