RE: HASH_JOIN on RBO?

From: Steve Adams <steve.adams_at_ixora.com.au>
Date: Wed, 13 Sep 2000 12:05:31 +1000
Message-Id: <10617.116778@fatcity.com>

Hi Chuck,

It sounds like there is some syntax error in the hint so that it just has the effect of forcing CBO to be used despite the absence of statistics.

@ Regards,
@ Steve Adams
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-----Original Message-----
From: Chuck Hamilton [mailto:chuck_hamilton_at_yahoo.com] Sent: Wednesday, 13 September 2000 7:31
To: Multiple recipients of list ORACLE-L Subject: HASH_JOIN on RBO?

I have a query with a RULE hint, but the execution plan is show hash joins. Is this something new in the 8.1.5 optimizer? It used to be that you could only get HASH joins with CBO. Also, each of the operations is showing a cost and cardinality even though none of the tables have stats. The net result is I'm getting a horrible execution plan that includes Cartesian merges and runs for hours when previously this query ran in minutes. Any ideas? Received on Tue Sep 12 2000 - 21:05:31 CDT