From: | "Bjorn T Johansen" <btj(at)havleik(dot)no> |
---|---|
To: | pgsql-general(at)postgresql(dot)org |
Subject: | Re: RE : Seq scan of table? |
Date: | 2003-09-05 06:55:24 |
Message-ID: | 14218.193.212.14.12.1062744924.squirrel@www.havleik.no |
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Thread: | |
Lists: | pgsql-general pgsql-performance |
Well, I just checked and all the join fields are of the same type...
BTJ
> Hello,
>
>> I am trying to tune my database and I discovered one select
>> that does a seq scan on a table but I can't see why... All
>> the join fields are indexed and I am returning just one
>> record, so no sort is done. Does it just pick seq scan for
>> the heck of it or is it a reason?
>
> Are the join fields both of the exactly same type ? If no (eg : INT2 and
> INT4)
> you must cast in order to have the same type.
>
> If the join fields are not of the same type, PostgreSQL will do a seq
> scan.
>
> I had exactly the same problem and learned here that tip :-)
>
> Hope this help,
>
> ---------------------------------------
> Bruno BAGUETTE - pgsql-ml(at)baguette(dot)net
>
>
>
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