On Mon, Aug 30, 2010 at 12:20 AM, Gerhard Wiesinger <li...@wiesinger.com> wrote: > Hello, > > I just upgraded with pg_dump/restore from PostgreSQL 8.3.11 to 8.4.4 but I'm > having major performance problems with a query with many left joins. Problem > is that costs are now very, very, very high (was ok in 8.3). Analyze has > been done. Indexes are of course there. > > -> Merge Left Join > (cost=1750660.22..4273805884876845789194861338991916289697885665127154313046252183850255795798561612107149662486528.00 > rows=238233578115856634454073334945297075430094545596765511255148896328828230572227215727052643001958400 > width=16) > Merge Cond: (l.id = d2000903.fk_id)
Wow! Other than an incredibly high cost AND row estimate, was the query plan the same on 8.3 or different? > Details with execution plan can be found at: > http://www.wiesinger.com/tmp/pg_perf_84.txt What's up with the "(actual time=.. rows= loops=) " in the explain analyze? > I know that the data model is key/value pairs but it worked well in 8.3. I > need this flexibility. > > Any ideas? Not really. I would like an explain analyze from both 8.3 and 8.4. Are they tuned the same, things like work mem and default stats target? -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
