On 15 July 2010 15:41, Patrick Donlin <pdonlin@xxxxxxxxx> wrote: > I have two servers with equal specs, one of them running 8.3.7 and the new > server running 8.4.4. The only tweak I have made from the default install > (from Ubuntu repositories) is increasing shared_buffers to 768MB. Both > servers are running 64-bit, but are different releases of Ubuntu. > > This is the query I am running: > > SELECT DISTINCT test.tid, testresult.trscore, testresult.trpossiblescore, > testresult.trstart, > testresult.trfinish, testresult.trscorebreakdown, testresult.fk_sid, > testresult.fk_tid, test.tname, > qr.qrscore, qr.qrtotalscore, testresult.trid, qr.qrid > FROM testresult, test, questionresult qr > WHERE test.tid = testresult.fk_tid AND qr.fk_trid = testresult.trid > ORDER BY test.tid; > > Results when running on the v8.3.7 server.... > Total query runtime: 32185 ms. > 700536 rows retrieved. > > Results when running on the v8.4.4 server.... > Total query runtime: 164227 ms. > 700536 rows retrieved. > > Results when running on a different v8.4.4 server with slightly faster > hardware and shared_buffers at 1024MB.... > (this one has a few more rows of data due to this being the server that is > currently live, so it has more recent data) > Total query runtime: 157931 ms. > 700556 rows retrieved. > > > Anyone have any ideas on where I should start looking to figure this out? I > didn't perform any special steps when moving to v8.4, I just did a pg_dump > from the 8.3 server and restored it on the new 8.4 servers. Maybe that is > where I made a mistake. > > Thanks! > Patrick > First thing to check is did you do a VACUUM ANALYZE on the database? Thom -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
