Re: Postmaster won't -HUP
От | Tom Lane |
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Тема | Re: Postmaster won't -HUP |
Дата | |
Msg-id | 26508.959896713@sss.pgh.pa.us обсуждение исходный текст |
Ответ на | Re: Postmaster won't -HUP (Jerry Lynde <jlynde@diligence.com>) |
Ответы |
Re: Postmaster won't -HUP
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Список | pgsql-general |
Jerry Lynde <jlynde@diligence.com> writes: >>>> They are all indexed, the DOB index is actually DOBYear DOBDay and >>>> DOBMonth and all 5 fields are indexed >> >> Do you have 5 indexes or do you have an index that spans more than one >> field? > Sorry for being less than explicit. There are 5 separate indices, one per > field. So your query is really something more like ... WHERE firstname = 'joe' AND lastname = 'blow' AND DOByear = 1999 AND DOBmonth = 1 AND DOBday = 1 ? The problem here is that only one index can be used in any individual scan. If I were the optimizer I'd probably figure that lastname is going to be the most selective of the five available choices, too. I'd suggest storing the DOB as *one* field of type 'date'. You can pull out the subparts for display with date_part() when you need to, but for searches you'll be a lot better off with WHERE DOB = '1999-01-01' regards, tom lane
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