Re: [GENERAL] Re: Data warehousing
От | Chris Bitmead |
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Тема | Re: [GENERAL] Re: Data warehousing |
Дата | |
Msg-id | 377771D4.C603FEB2@bigfoot.com обсуждение исходный текст |
Ответ на | Re: Data warehousing (Herouth Maoz <herouth@oumail.openu.ac.il>) |
Ответы |
Re: [GENERAL] Re: Data warehousing
Re: [GENERAL] Re: Data warehousing |
Список | pgsql-general |
Herouth Maoz wrote: > Maybe I'm missing the point here, but it seems to me that if > you simply use indices not as key definitions but as query > accelerators (as in "index the living daylights out of"), then > you may as well define a separate index on each and every > field. Why do multiple-field indices in such a case? Why do multi-field indexes? Umm. How about to avoid doing a sequential scan? If your query depends on multiple fields then once you've found the set based on the first index you would have to sequential scan that subset based on the second condition, unless you have a multi-field index.
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