Hi Rchard, I've created 3 test samples. A C++ and two VB.NET variants.
1. "SQLitePerfTest - C++ " runs very fast. 50.000 queries in 8 or 9 seconds; 2. "SQLitePerfTest - VB.net runs very fast. 50.000 queries in 7 or 8 seconds. (Without the GROUP_CONCAT function that is;) 3. "SQLitePerfTest - VB.net which runs slow, 50.000 queries in 5 or 6 minutes; Thank you for your time and effort and hope to hear from you. With regards, Peter Kraijenbrink FixHet - Systeembeheer Geestdorp 22-II 3444 BD Woerden Tel: 0348-410220 Gsm: 06 - 27231926 Web: www.fixhet.nl Mail: kraijenbr...@fixhet.nl =================== Disclaimer ===================== Dit e-mailbericht is vertrouwelijk en uitsluitend bedoeld voor de geadresseerde. Indien u niet de geadresseerde bent wordt u verzocht de afzender hiervan in kennis te stellen en dit bericht te vernietigen. FixHet - Systeembeheer aanvaardt geen enkele aansprakelijkheid voor enigerlei schade voortvloeiend uit het gebruik en/of acceptatie van de inhoud van het bericht. Bij twijfel verzoeken wij u een kopie op te vragen. Deze e-mail is gescand op virussen met Kaspersky Antivirus. ================================================= -----Original Message----- From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of Richard Hipp Sent: donderdag 25 september 2014 17:46 To: General Discussion of SQLite Database Subject: Re: [sqlite] group_concat query performance On Thu, Sep 25, 2014 at 9:34 AM, Richard Hipp <d...@sqlite.org> wrote: > Thanks for the schema. Unfortunately, that was insufficient to > reproduce the problem. Are you able to send me the actual database > file, via private email? > Thanks for sending the data. But I'm still not able to reproduce the problem. I tried running this script against your database: .open /home/drh/Downloads/Journal.dat .tables PRAGMA integrity_check; .timer on SELECT GROUP_CONCAT(Parent.fkintFolderID,'\') FilePath FROM tblFolderNestedSets Node , tblFolderNestedSets Parent WHERE Node.intLeft BETWEEN Parent.intLeft AND Parent.intRight AND Parent.fkintSessionID = Node.fkintSessionID AND Node.fkintSessionID = 1817 AND Node.fkintFolderID = 1937926; .print --------------------------------------------------- SELECT Parent.fkintFolderID FilePath FROM tblFolderNestedSets Node , tblFolderNestedSets Parent WHERE Node.intLeft BETWEEN Parent.intLeft AND Parent.intRight AND Parent.fkintSessionID = Node.fkintSessionID AND Node.fkintSessionID = 1817 AND Node.fkintFolderID = 1937926; The output I get back is: tblCabinets tblFiles tblSessions tblDataParts tblFolderNames vw_FileParts tblFileNames tblFolderNestedSets vw_Files tblFileParts tblFolders vw_Folders ok Run Time: real 0.000 user 0.000084 sys 0.000000 --------------------------------------------------- Run Time: real 0.000 user 0.000061 sys 0.000000 As you can see, neither query is returning any result and neither query is taking an measurable amount of time. Do you have any suggestions on what I can do differently in order to recreate your problem? -- D. Richard Hipp d...@sqlite.org _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
