Re: Select * is very slow
От | Thomas Kellerer |
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Тема | Re: Select * is very slow |
Дата | |
Msg-id | ib9as0$a8s$1@dough.gmane.org обсуждение исходный текст |
Ответ на | Re: Select * is very slow ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>) |
Ответы |
Re: Select * is very slow
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Список | pgsql-performance |
Kevin Grittner, 08.11.2010 18:01: > "shaiju.ck"<shaiju.ck@gmail.com> wrote: > >> The table have 200 records now. >> Select * from employee takes 15 seconds to fetch the data!!! >> Which seems to be very slow. >> But when I say select id,name from empoyee it executes in 30ms. >> Same pefromance if I say select count(*) from emloyee. > > You haven't given nearly enough information for anyone to diagnose > the issues with any certainty. Earlier responses have asked for > some particularly important information, and I would add a request > to see the output from `VACUUM VERBOSE employee;`. Beyond that, you > might want to review this page for checks you can make yourself, and > information which you could provide to allow people to give more > informed advice: Do you really think that VACCUM is the problem? If the OP only selects two columns it is apparently fast. If he selects all columns it's slow, so I wouldn't suspect dead tuples here. My bet is that there are some really large text columns in there... He has asked the same question here: http://forums.devshed.com/postgresql-help-21/select-is-very-slow-761130.html but has also failed to answer the question about the table details... Regards Thomas
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