Re: DROP TABLE and autovacuum

Alvaro Herrera <alvherre(at)commandprompt(dot)com> wrote:

> Something worth considering, though unrelated to the topic at hand: what
> happens with the table stats after CLUSTER? Should we cause an ANALYZE
> afterwards? We could end up running with outdated statistics.

We don't invalidate the value statistics in pg_stats by ANALYZE presently.

Also, the runtime statistics are not invalidated -- it cound be a bug.
pgstat_drop_relation() is expecting relid (pg_class.oid) as the argument,
but we pass it relfilenode.

[storage/smgr/smgr.c]
static void
smgr_internal_unlink(RelFileNode rnode, int which, bool isTemp, bool isRedo)
{
...
/*
* Tell the stats collector to forget it immediately, too. Skip this in
* recovery mode, since the stats collector likely isn't running (and if
* it is, pgstat.c will get confused because we aren't a real backend
* process).
*/
if (!InRecovery)
pgstat_drop_relation(rnode.relNode);

...
}

Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center