Re: Avoiding bad prepared-statement plans.
Dimitri Fontaine <dfontaine@hi-media.com>
From: Dimitri Fontaine <dfontaine@hi-media.com>
To: Jeroen Vermeulen <jtv@xs4all.nl>
Cc: Yeb Havinga <yebhavinga@gmail.com>, pgsql-hackers@postgresql.org
Date: 2010-02-09T22:21:43Z
Lists: pgsql-hackers
Jeroen Vermeulen <jtv@xs4all.nl> writes: > I think we should be careful not to over-think this. Planning isn't *that* > costly, so apply Amdahl's Law liberally. I'm proposing some easy things we > could do without adding much overhead or maintenance burden; I've been > assuming that getting intimate with the planner would risk those advantages. On a project where performance is a must (5ms per query is about all you can ask) I have queries for which planning is 40+ ms and execute 2 to 5 ms (dataset fits in RAM, by design). I'm then abusing pgbouncer so that the PREPARE is shared by a lot of clients, all the ones landing into the session (transaction pooling). See preprepare to get a better idea, even if we're yet to run it (it's being used in production elsewhere, though, I've been told). http://preprepare.projects.postgresql.org/ Regards, -- dim