On Wed, Apr 18, 2012 at 12:52 PM, Robert Haas <robertmh...@gmail.com> wrote: > On Wed, Apr 18, 2012 at 12:40 PM, Emanuel Calvo <postgres....@gmail.com> > wrote: >>> I'm not sure what you're unhappy about. It seems that the query >>> planner picked the fastest plan (a sequential scan) and then when you >>> disabled that it picked the second-fastest plan (an index-only scan). >>> >>> The index-only scan would have a chance of beating the sequential scan >>> if the table had been recently vacuumed, but not in the case where >>> every row is going to require a heap fetch. >> >> Oh, I see now. Honestly, I thought it wasn't necessary to make a heap >> fetch. The table >> doesn't have any modifications, but with the vacuum the cost changed. > > Ah, I see. Yeah, I think you're not going to be the first person to > not realize that, especially since we haven't changed the rules for > autovacuuming, and therefore you can't count on autovac to correct the > problem for you. :-(
And by "the first person" I of course meant "the last person". -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
