Reports (2.5) and Optimization Method?

From: Steven Peacock <speacock_at_dst-usa.com>
Date: Tue, 28 Jul 1998 12:45:32 GMT
Message-ID: <6pki2d$fmj$1_at_news.iag.net>



[Quoted] We had a group of reports that were running fairly slow (Took up to a half hour to run). So we took the queries out of the reports and explained them in sql*plus. Two things were immediately evident 1) The queries actually ran within 1 minute in SQL*Plus 2) The explain plans showed that the queries were actually fairly well tuned.

Finally after a couple of days of messing around with this, we put a hint in the query while running sql*plus to force use of rule based optimization. All of a sudden the query in SQL*PLUS took as long to run as the report did. We added a hint in the report query to cause cost based optimization (FIRST_ROWS) to be used, and now the reports run in about three minutes instead of 30.

The question. It would seem from this one experience that reports is always running in rule based optimizer mode, is this the case?

Steven Peacock Received on Tue Jul 28 1998 - 14:45:32 CEST

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