Almost any cross dbms migration shows a drop in performance. The engine effectively trains developers and administrators in what works and what doesn't. The initial migration thus compares a tuned to an untuned version.
/Aaron ----- Original Message ----- From: "Josh Berkus" <[EMAIL PROTECTED]> To: "Gary Doades" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Saturday, April 03, 2004 1:59 PM Subject: Re: [PERFORM] PostgreSQL and Linux 2.6 kernel. > Gary, > > > There are no indexes on the columns involved in the update, they are > > not required for my usual select statements. This is an attempt to > > slightly denormalise the design to get the performance up comparable > > to SQL Server 2000. We hope to move some of our databases over to > > PostgreSQL later in the year and this is part of the ongoing testing. > > SQLServer's query optimiser is a bit smarter that PostgreSQL's (yet) > > so I am hand optimising some of the more frequently used > > SQL and/or tweaking the database design slightly. > > Hmmm ... that hasn't been my general experience on complex queries. However, > it may be due to a difference in ANALYZE statistics. I'd love to see you > increase your default_stats_target, re-analyze, and see if PostgreSQL gets > "smarter". > > -- > -Josh Berkus > Aglio Database Solutions > San Francisco > > > ---------------------------(end of broadcast)--------------------------- > TIP 3: if posting/reading through Usenet, please send an appropriate > subscribe-nomail command to [EMAIL PROTECTED] so that your > message can get through to the mailing list cleanly > ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org