If your optimizer is set to cost based and the tables concerned have been
analyzed between the change in execution plan, that could account for the
alteration.
> -----Original Message-----
> From: Dan.Hubler_at_midata.com [SMTP:Dan.Hubler_at_midata.com]
> Sent: Monday, June 26, 2000 3:16 PM
> To: Multiple recipients of list ORACLE-L
> Subject: Hash join not being used
>
>
> We have a query that is a good candidate for a hash-join operation.
> As a matter of fact, when we force it to use a hash-type join (with a
> hint), the
> elapsed time of the query goes from 90 minutes to about 2 minutes.
>
> However, we are unable to force it to use a hash-join, without using the
> hint.
>
> What perplexes us is that a month ago, the query was using a hash-join on
> its
> own, without our intervention.
>
> Any clues as to why the optimizer would change its mind and stop using a
> hash-join?
>
>
>
> --
> Author:
> INET: Dan.Hubler_at_midata.com
>
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Received on Mon Jun 26 2000 - 08:46:16 CDT
