Re: Dealing with complex queries
От | Jeff Eckermann |
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Тема | Re: Dealing with complex queries |
Дата | |
Msg-id | 20030204190736.85888.qmail@web20802.mail.yahoo.com обсуждение исходный текст |
Ответ на | Re: Dealing with complex queries (Francisco Reyes <lists@natserv.com>) |
Ответы |
Re: Dealing with complex queries
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Список | pgsql-general |
Try creating an index on the substrings: you will need to wrap the substring in a function marked "immutable" (or "with (iscachable)" for versions prior to 7.3) for the index to be of any use. I have done a lot of the sort of thing you describe, with good results using that method. --- Francisco Reyes <lists@natserv.com> wrote: > On Tue, 4 Feb 2003, Bruno Wolff III wrote: > > > On Mon, Feb 03, 2003 at 16:32:10 -0500, > > Francisco Reyes <lists@natserv.com> wrote: > > > Any hints suggestions on dealing with complex > queries. > > > > > substring(ppl.carried_as from 1 for 3) > > > = substring(jc.last from 1 for > 3) and > > > > Joining on substrings is a good sign that your > design needs rethinking. > > The tables in the substring comparison are some of > our tables compared > to tables supplied by another company. It is a fact > that the names don't > always match and have variations. > > The whole excersise is to match by names to then > populate our table with > their keys so in the future we can match by keys in > feeds we receive from > them. > > > ---------------------------(end of > broadcast)--------------------------- > TIP 5: Have you checked our extensive FAQ? > > http://www.postgresql.org/users-lounge/docs/faq.html __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com
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