Re: PGA_AGGREGATE_TARGET sizing of work areas and HJ cost

From: Grzegorz <>
Date: Fri, 29 May 2009 18:35:52 +0200
Message-ID: <gvp2t7$moa$> pisze:
> On May 29, 12:14 pm, Grzegorz <> wrote:

>> Hi,
>> I'm doing some investigations
>> because of query plan changing in the same session (from NL Index RS to
>> HJ FTS), and got question about Hash_Join_Area_Size when
>> work_area_policy=auto.
>> Is that possible that the same session can have different
>> HJAS for same query ?
>> When auto pga allocation is in place its quite possible in my opinion.
>> Looks like depending on instance workload (in PGA terms) some queries
>> may switch between NL Index RS and HJ FTS in the same session.
>> I'm on .
>> Regards.
>> GG

> Are you using bind variables?

Well yes :) and I've got histograms (deadly combo). But this is not related, because You can do that wo BV just manipulating   hash_area_size . No need for hard parse (sql modification/flush). Regards.
GG Received on Fri May 29 2009 - 11:35:52 CDT

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