PGA_AGGREGATE_TARGET sizing of work areas and HJ cost

Giganews Newsgroups
Subject: PGA_AGGREGATE_TARGET sizing of work areas and HJ cost
Posted by:  Grzegorz (fgrzegorz…@finteria.pl)
Date: Fri, 29 May 2009

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 9.2.0.8 .
Regards.
GG

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