>Zitat von azurIt <azu...@pobox.sk>: > >> Hi, >> >> i'm having some MySQL performance difficulties so i started to >> search what can i do better. My table 'File' had these indexes >> created: >> CREATE INDEX file_jobid_idx on File (JobId); >> CREATE INDEX file_jpf_idx on File (JobId, PathId, FilenameId); >> >> Which looks correct according to documentation: >> http://www.bacula.org/en/dev-manual/main/main/Catalog_Maintenance.html >> >> BUT! The first index apperas to be unneeded as it's part of the >> second index. According to MySQL documentation, 'any leftmost prefix >> of the index can be used by the optimizer to find row': >> http://dev.mysql.com/doc/refman/5.5/en/multiple-column-indexes.html >> >> I suggest to remove it. >> >> azur > >Would also apply to PostgreSQL i guess: >http://www.postgresql.org/docs/9.2/interactive/indexes-multicolumn.html > >Any comment why the additional single column index could be useful?
No statement from developers regarding this? azur ------------------------------------------------------------------------------ Get 100% visibility into Java/.NET code with AppDynamics Lite! It's a free troubleshooting tool designed for production. Get down to code-level detail for bottlenecks, with <2% overhead. Download for free and get started troubleshooting in minutes. http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
