Re: Relation of indices to ANALYZE - Mailing list pgsql-performance

From Tom Lane
Subject Re: Relation of indices to ANALYZE
Date
Msg-id 5740.1058466436@sss.pgh.pa.us
Whole thread Raw
In response to Relation of indices to ANALYZE  (Bill Moran <wmoran@potentialtech.com>)
Responses Re: Relation of indices to ANALYZE  (Bill Moran <wmoran@potentialtech.com>)
List pgsql-performance
Bill Moran <wmoran@potentialtech.com> writes:
> Specifically, I'm wondering if I should do
> the ANALYZE before or after I recreate the indexes, or whether it matters.

At the moment it does not matter --- ANALYZE computes statistics for
each column of a table regardless of what indexes exist.

There has been some talk of trying to compute statistics for the
contents of functional indexes.  Also, if we ever do anything about
computing multicolumn correlation statistics, we'd likely choose which
ones are worth computing based on the presence of multicolumn indexes.
So if you want to future-proof your code I'd recommend recreating the
indexes before you ANALYZE.

            regards, tom lane

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