Re: Query tuning help
От | Klint Gore |
---|---|
Тема | Re: Query tuning help |
Дата | |
Msg-id | 427EE44D37F.5629KG@129.180.47.120 обсуждение исходный текст |
Ответ на | Re: Query tuning help (Dan Harris <fbsd@drivefaster.net>) |
Список | pgsql-performance |
On Sun, 8 May 2005 20:31:38 -0600, Dan Harris <fbsd@drivefaster.net> wrote: > Duly noted. If this method can search across rows, I'm willing to > accept this overhead for the speed it would add. You could use intersect to search across rows. Using tsearch2 will look up the RED and CORVETTE using the index and intersect will pull out the commmon rows. > In the meantime, is there any way I can reach my goal without Tsearch2 > by just restructuring my query to narrow down the results by date > first, then seq scan for the 'likes'? select distinct em.incidentid, ea.recordtext as retdata, eg.long, eg.lat >from ea, em, eg, ( select ea.incidentid from ea, em where em.incidentid = ea.incidentid and em.entrydate >= '2005-1-1 00:00' and em.entrydate <= '2005-5-9 00:00' and recordtext like '%RED%' intersect select ea.incidentid from ea, em where em.incidentid = ea.incidentid and em.entrydate >= '2005-1-1 00:00' and em.entrydate <= '2005-5-9 00:00' and recordtext like '%CORVETTE%' ) as iid where em.incidentid = ea.incidentid and em.incidentid = eg.incidentid and em.entrydate >= '2005-1-1 00:00' and em.entrydate <= '2005-5-9 00:00' and ea.incidentid = iid.incidentid and ( recordtext like '%RED%' or recordtext like '%CORVETTE%' ) order by em.entrydate klint. +---------------------------------------+-----------------+ : Klint Gore : "Non rhyming : : EMail : kg@kgb.une.edu.au : slang - the : : Snail : A.B.R.I. : possibilities : : Mail University of New England : are useless" : : Armidale NSW 2351 Australia : L.J.J. : : Fax : +61 2 6772 5376 : : +---------------------------------------+-----------------+
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