Lol... we just had a long discussion about sqlite_stat2 and ANALYZE command.
I removed these from my code, since the command should not be used except for
rare cases :P
Should I re-add my ANALYZE-code and ask my original question again? Confused :P
> From: d...@sqlite.org
> Date: Sat, 12 Feb 2011 10:27:40 -0500
> To: sqlite-...@sqlite.org; sqlite-users@sqlite.org
> Subject: [sqlite] SQLite version 3.7.6 testing
>
> The scheduled release of SQLite version 3.7.6 is mid-April. We are still
> two months away. However, version 3.7.6 will contain a lot of pent-up
> changes and so your advance testing of this release will be appreciated.
>
> The latest pre-3.7.6 code can be found here:
>
> http://www.sqlite.org/draft/download.html
>
> And sketchy information about the changes added (so far) can be seen here:
>
> http://www.sqlite.org/draft/releaselog/3_7_6.html
>
> Of particular concern in 3.7.6 are some tweaks we've done to the query
> planner. The query planner is the part of SQLite that decides on the best
> and fastest algorithm to use to satisfy your queries. SQLite uses a
> cost-based query planner. In other words, it tries to estimate the CPU and
> disk I/O load used by various alternative algorithms and it selects the
> algorithm with the lowest estimated cost. The problem with this approach is
> that the cost really is an estimate based on incomplete information, and so
> it sometimes comes out wrong. The cost functions for 3.7.6 have been
> enhanced to be more accurate (we believe) particularly if SQLite is compiled
> using SQLITE_ENABLE_STAT2 and you run ANALYZE on your database files to
> gather statistics. But there could be instances where the cost estimates
> are not as good as before, resulting in performance regressions.
>
> So, if you have the ability to download an early snapshot of SQLite 3.7.6
> and compile it into your application for performance testing purposes, we
> would really appreciate it if you would do so. And do so sooner rather than
> later so that we can have plenty of time to fix an issues you discover prior
> to the 3.7.6 release. If the query planner in 3.7.6 improves the
> performance of your application, we'd also like to hear about that too.
>
> I'll try to post snapshots of 3.7.6 on a regular basis so that you can
> download and compile a fairly recent version at any time. Please pester me
> if I forget.
>
> Thanks for your help.
> --
> D. Richard Hipp
> d...@sqlite.org
> _______________________________________________
> sqlite-users mailing list
> sqlite-users@sqlite.org
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