> -----Original Message-----
> From: Bruce Momjian [mailto:pgman(at)candle(dot)pha(dot)pa(dot)us]
> > Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > > That certainly would make sense. We have hesitated to gather more
> > > statistics because of the time involved. Fuller statistics
> on just the
> > > indexed columns could be a big win and be done fairly quickly because
> > > the rows are already sorted in the index.
> > Yeah, a scan over just the index itself would be a perfect way to
> > gather stats. The normal objection to it (can't tell whether entries
> > correspond to currently-valid tuples) doesn't apply, because we don't
> > really care whether the stats are perfectly accurate.
> > Should put this in TODO, along with something about splitting the
> > ANALYZE function out of VACUUM and making it invokable as a separate
> > statement.
> * Remove ANALYZE from VACUUM so it can be run separately without locks
> * Gather more accurate statistics using indexes
Gathering statistics using indexes on-fly is best.
However VACUUM(without ANALYZE) already scans all indexes using
vc_scanoneind()/vc_vaconeind(). Isn't it availble anyway ?
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