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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? Received on Mon Jun 26 2000 - 08:05:23 CDT