Re: Indexes?
| От | Bjørn T Johansen |
|---|---|
| Тема | Re: Indexes? |
| Дата | |
| Msg-id | 41B00489.1070401@havleik.no обсуждение исходный текст |
| Ответ на | Re: Indexes? (Bruno Wolff III <bruno@wolff.to>) |
| Список | pgsql-general |
Well, then it's decided to try with two indexes... Thx... :) BTJ Bruno Wolff III wrote: > On Wed, Dec 01, 2004 at 23:16:48 -0800, > Vincent Hikida <vhikida@inreach.com> wrote: > >>I believe that it is better to have a concatenated key of >>(toDate,FromDate). The reason the toDate should come first is that for more >>"recent" records, finding curDates less than toDate is much more selective >>than finding curDates greater than fromDate. Actually I'm not sure if >>fromDate is that helpful either as part of the concatenated key (it >>probably depends) but definitely not by itself. > > > I combined index won't be very useful for the kind of search he is doing. > And not having an index on FromDate could hurt in some cases depending > on the distribution of values. > > ---------------------------(end of broadcast)--------------------------- > TIP 2: you can get off all lists at once with the unregister command > (send "unregister YourEmailAddressHere" to majordomo@postgresql.org)
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