Re: Tuning Advice
Date: Fri, 27 Apr 2018 17:58:52 +0000
Message-ID: <LO1P123MB09774EA00D83F69B3D6DAC8CA58D0_at_LO1P123MB0977.GBRP123.PROD.OUTLOOK.COM>
Another ought about select vs, insert as select, vs. CTAS.
Even in the absence of indexes the middle one will generate a lot of redo, but if the database is in noarchivelog mode the CTAS will be a nologging operation. It's possible that could make some difference to run time.
Regards
Jonathan Lewis
From: oracle-l-bounce_at_freelists.org <oracle-l-bounce_at_freelists.org> on behalf of Sheehan, Jeremy <JEREMY.SHEEHAN_at_fpl.com> Sent: 27 April 2018 16:50
To: ORACLE-L
Subject: Tuning Advice
Hello Gurus,
Oracle 12.1.0.2
AIX 7.1
I have a query that runs fairly well. Takes about 8 minutes to run, nothing terrible about it (no huge FTS, joins seem to be in place correctly). When I try to do an insert into TABLE as SELECT, it picks a completely different execution plan and never finishes. The really odd thing is that it works great when using CTAS or initial creation of a MV.
Any suggestion on how I can have the optimizer not use a specific execution plan or any session level parameters that would have it use a different execution plan?
Thanks in advance!
Jeremy
-- http://www.freelists.org/webpage/oracle-lReceived on Fri Apr 27 2018 - 19:58:52 CEST