On Apr 4, 2013, at 2:49 PM, Franck Routier <franck.rout...@axege.com> wrote:
> Le 04/04/2013 18:25, Tom Lane a écrit : >> Franck Routier <franck.rout...@axege.com> writes: >>> Right, explain alone takes 3.6 seconds, so the time really seems to go >>> query planning... >> Well, you've not shown us the query, so it's all going to be >> speculation. But maybe you have some extremely expensive function that >> the planner is evaluating to fold to a constant, or something like that? >> The generated plan isn't terribly complicated, but we can't see what >> was required to produce it. >> >> regards, tom lane >> >> > The request is not using any function. It looks like this: > > SELECT * > FROM sanrss > LEFT JOIN sanrum ON sanrum.sanrum___rforefide = > sanrss.sanrss___rforefide AND sanrum.sanrum___rfovsnide = > sanrss.sanrss___rfovsnide AND sanrum.sanrum___sanrsside = sanrss.sanrsside > LEFT JOIN sanact ON sanact.sanact___rforefide = > sanrum.sanrum___rforefide AND sanact.sanact___rfovsnide = > sanrum.sanrum___rfovsnide AND sanact.sanact___sanrsside = > sanrum.sanrum___sanrsside AND sanact.sanact___sanrumide = sanrum.sanrumide > AND sanact.sanact___sanrumide IS NOT NULL AND > sanact.sanact___rsanopide='CCAM' > LEFT JOIN sandia ON sandia.sandia___rforefide = > sanrum.sanrum___rforefide AND sandia.sandia___rfovsnide = > sanrum.sanrum___rfovsnide AND sandia.sandia___sanrsside = > sanrum.sanrum___sanrsside AND sandia.sandia___sanrumide = sanrum.sanrumide > AND sandia.sandiasig=1 > LEFT JOIN saneds ON sanrss.sanrss___rforefide = > saneds.saneds___rforefide AND sanrss.sanrss___rfovsnide = > saneds.saneds___rfovsnide AND sanrss.sanrss___sanedside = saneds.sanedside > LEFT JOIN rsaidp ON saneds.saneds___rforefide = > rsaidp.rsaidp___rforefide AND saneds.saneds___rsaidpide = rsaidp.rsaidpide > WHERE sanrss.sanrss___rforefide = 'CHCL' AND > sanrss.sanrss___rfovsnide = '201012_600' AND sanrss.sanrsside = '1188100' > ORDER BY sanrum.sanrumord, sanrum.sanrumide > > Schema looks like this : > rsaidp > | > v > sanrss -------- > | | > v v > sanrum sandia > | > v > sanact > > > Primary keys are most made of several varchars. Foreign keys do exist. Query > is getting these data for one specific sanrss. > This used to take around 50ms to execute, and is now taking 3.5 seconds. And > it looks like this is spent computing a query plan... > > I also tried: PREPARE qry(id) as select .... > The prepare takes 3.5 seconds. Execute qry(value) takes a few milliseconds... > > Regards, > Franck Is it only this query or all queries?
