Re: Reports (2.5) and Optimization Method?

Oracle Reports will not automatically use cost-base optimization. It's the database/table optimization setting governs.

Steven Peacock wrote:

> 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 Thu Jul 30 1998 - 08:29:01 CEST