From: | Bjørn T Johansen <btj(at)havleik(dot)no> |
---|---|
To: | pgsql-general(at)postgresql(dot)org |
Subject: | Re: Indexes? |
Date: | 2004-12-03 06:15:37 |
Message-ID: | 41B00489.1070401@havleik.no |
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Thread: | |
Lists: | 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(at)inreach(dot)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.
>
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