Re: Simple SQL question
От | Daniel Henrique Alves Lima |
---|---|
Тема | Re: Simple SQL question |
Дата | |
Msg-id | 404D599C.80101@yahoo.com.br обсуждение исходный текст |
Ответ на | Re: Simple SQL question ("Iain" <iain@mst.co.jp>) |
Список | pgsql-sql |
Ok, Iain. Thanks for the tip ! Iain wrote: >Just a note based on my experience, if you are going to to use IN processing >then there is a good chance that the index isn't going to be used. In some >recent tests I did, the index stopped being used after I put 3 or more items >in the IN list. You should build some representatve examples of the select >and test them using "ANALYSE SELECT ..." .I'm using 7.4.1. > >The result from the select is the same, even if you don't make an index on >the function result.It's just a performance consideration. If the index >isn't used, then you don't need to create it. > >regards >Iain >----- Original Message ----- >From: "Daniel Henrique Alves Lima" <email_daniel_h@yahoo.com.br> >To: <pgsql-sql@postgresql.org> >Sent: Tuesday, March 09, 2004 1:21 PM >Subject: Re: [SQL] Simple SQL question > > > >
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