Re: ANALYZE estimates very wrong reltuples

Qingbo Zhou wrote:
> I have a table which has ~26M records in it. But pg_class shows ~35M in the "reltuples" column.
> last_autovacuum is null, and last_autoanalyze was just on yesterday.
>
> I tried running vacuum analyze on it, but the analyze result shows:
>
> INFO: "[table name]": scanned 30000 of 950145 pages, containing 805842 live rows and 11109 dead rows;
> 30000 rows in sample, 42266462 estimated total rows
>
>
> Even worse estimates. I know that it's doing an estimate, but it's too wrong. I have another table for
> which pg_class estimates 3 times the actual number of rows.
>
> I'm using 9.1.3 [...]

Could you try with different settings for default_statistics_target
(1000, 10000) and see if that changes the result of
ANALYZE VERBOSE?

Yours,
Laurenz Albe