On Thu, Sep 1, 2016 at 10:32 AM, Patrick B <patrickbake...@gmail.com> wrote:
> > > 2016-09-01 11:53 GMT+12:00 Venkata B Nagothi <nag1...@gmail.com>: > >> >> On Thu, Sep 1, 2016 at 8:41 AM, Patrick B <patrickbake...@gmail.com> >> wrote: >> >>> Hi guys, >>> >>> A dev has ran a VACUUM FULL command into our test database running >>> PostgreSQL 9.5 (I know... goddamn!!!!)... >>> >>> ... after the Vacuum Full, some queries start using SEQ scans instead of >>> indexes... >>> >>> Does that happen because of the size of the table? The table that I'm >>> referring to is 150MB big after the vacuum (Before was 1G)... >>> >> >> Yes, it is possible that sequential scans after vacuum full are cheaper >> than Index scans before vacuum full ? do you see improvement in query >> response times ? >> How does the cost differ ? >> >> Regards, >> Venkata B N >> >> Fujitsu Australia >> > > > Well... the response time was worst than when using index.. that's very > weird... I've re-created the indexes now a ran ANALYZE and the query is > using again the index.. just wanted understand what happened... > There you go.. Running ANALYZE made the difference. Whenever you execute VACUUM or VACUUM FULL make sure you execute ANALYZE so that latest stats are updated. Sorry, i should have mentioned this earlier. Regards, Venkata B N Fujitsu Australia
