select count(*) from table
where a_column =
( select cdk(123) from dual where rownum = 1 )
or you can use DISTINCT or a NO_MERGE hint - anything
to force the subquery to be evaluated in isolation
hth
connor
- David Turner <turner_at_tellme.com> wrote: > My
users are writing many of their own functions and
> it is causing performance to suffer
> on a few simple queries. For example, I have a query
> that just selects count(*) from a
> table. With the function
>
> select count(*) from a_table where a_column =
> cdk(1234567890);
>
> It takes 5 minutes
>
> By plugging in the result of the cdk function into
> the query
>
> select count(*) from a_table where a_column =
> 0987654321;
>
> It take .18 of a second.
>
> How can I tell the optimizer that the result of the
> function will be the same every
> time so you don't need to call it for every row? I
> can do this in the app but it would
> be cool to know if I can do this on the database
> side also.
>
> Thanks, Dave
>
> --
> Please see the official ORACLE-L FAQ:
> http://www.orafaq.com
> --
> Author: David Turner
> INET: turner_at_tellme.com
>
> Fat City Network Services -- (858) 538-5051 FAX:
> (858) 538-5051
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Connor McDonald
http://www.oracledba.co.uk (mirrored at
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Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: =?iso-8859-1?q?Connor=20McDonald?=
INET: hamcdc_at_yahoo.co.uk
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San Diego, California -- Public Internet access / Mailing Lists
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Received on Wed Jun 27 2001 - 14:24:54 CDT
