Re: adaptive cursor sharing and bind peeking

  • From: Mohamed Houri <mohamed.houri@xxxxxxxxx>
  • To: Jonathan Lewis <jonathan@xxxxxxxxxxxxxxxxxx>
  • Date: Thu, 30 May 2013 14:12:53 +0200

According to the tests I have done, I am inclined to say that Carlos
description is correct. If I have already a child cursor that is bind
sensitive, bind aware and shareable for a bind variable that favors (for
example an index range scan) and then I execute the same query with a
different bind variable which is also favoring the same index range scan,
It will share the same child cursor. I have to test that again but I am
quite confident that it will work as described.
However, I have found situations where this smooth ACS working is disturbed

Best regards

Mohamed Houri

2013/5/30 Jonathan Lewis <jonathan@xxxxxxxxxxxxxxxxxx>

> Carlos,
> This doesn't seem to agree with a blog post that Randolf Geist wrote some
> time ago:
> He does mention a bug, relating to ACS not working properly with PL/SQL,
> and presumably that's fixed by now; even so, "checking before every
> EXECUTION" doesn't seem to match his observations.
> Regards
> Jonathan Lewis
> ________________________________________
> From: oracle-l-bounce@xxxxxxxxxxxxx [oracle-l-bounce@xxxxxxxxxxxxx] on
> behalf of Carlos Sierra [carlos.sierra.usa@xxxxxxxxx]
> Sent: 30 May 2013 11:35
> To: ax.mount@xxxxxxxxx
> Cc: Christian Antognini; oracle-l@xxxxxxxxxxxxx
> Subject: Re: adaptive cursor sharing and bind peeking
> Once it is bind aware on every execution it looks at the values of binds
> ...--
> //

Bien Respectueusement
Mohamed Houri


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