On Fri, Jan 2, 2015 at 8:34 PM, Kevin Grittner <kgri...@ymail.com> wrote:
> Amit Kapila <amit.kapil...@gmail.com> wrote:
> > Notes for Committer -
> > There is one behavioural difference in the handling of
> > switch, when individual tables (by using -t option) are analyzed by
> > using this switch, patch will process (in case of concurrent jobs) all
> > given tables for stage-1 and then for stage-2 and so on whereas in the
> > unpatched code it will process all the three stages table by table
> > (table-1 all three stages, table-2 all three stages and so on).  I think
> > the new behaviour is okay as the same is done when this utility does
> > vacuum for whole database.
> IMV, the change is for the better.  The whole point of
> --analyze-in-stages is to get minimal statistics so that "good
> enough" plans will be built for most queries to allow a production
> database to be brought back on-line quickly, followed by generating
> increasing granularity (which takes longer but should help ensure
> "best plan") while the database is in use with the initial
> statistics.  Doing all three levels for one table before generating
> the rough statistics for the others doesn't help with that, so I
> see this change as fixing a bug.  Is it feasible to break that part
> out as a separate patch?

Currently as the patch stands the fix (or new behaviour) is only
implemented for the multiple jobs option, however to fix this in base
code a separate patch is required.

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com

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