2016-12-10 15:41 GMT+01:00 Adrian Klaver <adrian.kla...@aklaver.com>:
> On 12/10/2016 04:21 AM, Tom DalPozzo wrote: > >> Hi, >> my release is 9.5.4. >> a took a look over it. I guessed that counting could be slow because it >> needs to read everything and also that it can take advantage from an >> index. But I don't understand why the delay is after the updates for a >> > > Best guess, autovacuum kicked in and marked a bunch of rows as no longer > in play and thereby reduced the number of rows that needed to be counted. > > certain time and why WHERE..IN is much faster (ok, it's an index, but >> I'm reading all the rows). >> > > So per the second link have you tried something like: > > SELECT COUNT(*) FROM Table WHERE id > 0; > > >> Hi, no I did not (yet). But I guess that it would be similar to the one or to the other. I will give updates if I try. Regards Pupillo
