Re: reading vacuum verbosity - Mailing list pgsql-general

From Tom Lane
Subject Re: reading vacuum verbosity
Date
Msg-id 10807.1085161092@sss.pgh.pa.us
Whole thread Raw
In response to Re: reading vacuum verbosity  ("Ed L." <pgsql@bluepolka.net>)
List pgsql-general
"Ed L." <pgsql@bluepolka.net> writes:
> One oddity:  Even immediately after a vacuum or analyze, I notice that
> pg_class.reltuples is way off for this table, reporting 919373 rows
> when there are only ~284K.  pg_class.relpages looks precisely correct.
> This is PostgreSQL 7.3.4 on hppa2.0w-hp-hpux11.00, compiled by cc -Ae.

I'd expect reltuples to be correct after a VACUUM (or VACUUM ANALYZE).
But a plain ANALYZE sets it on the basis of a statistical estimate that
can be off quite a bit.  (Manfred's been looking at developing a better
estimate, which I hope will make it into 7.5.)

            regards, tom lane

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