RE: buffer advisor

And sometimes you do not. The question becomes would automatically converting constants to bind variables in all cases be more beneficial to the overall system verse flooding the shared pool with un-sharable SQL? In the case where the code runs better with a constant then there are Outlines and SQL Profiles to assist with tuning. Then again if Oracle works this way bind variable peeking might just peek on every execution for statements where it might make a difference.

From: Mark W. Farnham [mailto:mwf_at_rsiz.com] Sent: Wednesday, September 10, 2014 11:19 AM To: Powell, Mark; 'ORACLE-L'
Subject: RE: buffer advisor

Because sometimes you get a superior plan with a literal (by a lot), and then we'd have to hint one way or the other and we cannot do that because sometimes (often) we do not control the source code.

From: oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org> [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Powell, Mark Sent: Wednesday, September 10, 2014 11:03 AM To: 'ORACLE-L'
Subject: RE: buffer advisor

Why not automatically convert all constants to bind variables as part of the parse? This would make nearly identical SQL statements where only the value of the constant changes into identical statements supporting sharing.

From: oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org> [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Mark W. Farnham Sent: Tuesday, September 09, 2014 11:09 PM To: Hemant-K.Chitale_at_sc.com<mailto:Hemant-K.Chitale_at_sc.com>; 'ORACLE-L' Subject: RE: buffer advisor

There is no question that reusing reusable sql parses was a huge advance for scalability. But tossing non-reusable sql in the shared pool just puts extra pressure on the latches.

mwf

From: oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org> [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Chitale, Hemant K Sent: Tuesday, September 09, 2014 10:57 PM To: ORACLE-L
Subject: RE: buffer advisor

The shared pool came at the same time as database server pl/sql --- if I remember correctly. [there was forms pl/sql available earlier] Was there co-development or dependency ?

Hemant K Chitale

From: oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org> [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Mark W. Farnham Sent: Wednesday, September 10, 2014 10:48 AM To: iggy_fernandez_at_hotmail.com<mailto:iggy_fernandez_at_hotmail.com>; jeremy.schneider_at_ardentperf.com<mailto:jeremy.schneider_at_ardentperf.com> Cc: 'Seth Miller'; 'Oracle-L Freelists'
Subject: RE: buffer advisor

In fact, why not parse all sqls with literals privately? It worked just fine in V6.

mwf

From: oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org> [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Iggy Fernandez Sent: Tuesday, September 09, 2014 9:25 PM To: jeremy.schneider_at_ardentperf.com<mailto:jeremy.schneider_at_ardentperf.com> Cc: Seth Miller; Oracle-L Freelists
Subject: RE: buffer advisor

I wish that the ORA-4031 issue could be solved permanently #IfWishesWereHorses

Is a solution to this problem beyond the capabilities of mortals? #ShoutingIntoTheWind

Why is it necessary for a session to die if it cannot write to the shared pool? Why not just do what it needs to do even if it cannot share? #AskingTheObvious

Iggy

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