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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Configure SDU and TDU parameters to improve Performance
Juan,
According to following note it FORCE not SIMILAR produce unwanted results:
Shared Pool and Library Cache Performance Tuning <Note:62143.1> In Oracle9i, it is possible to set CURSOR_SHARING=SIMILAR. SIMILAR causes statements that may differ in some literals, but are otherwise identical, to share a cursor, unless the literals affect either the meaning of the statement or the degree to which the plan is optimized. This enhancement improves the usability of the parameter for situations where FORCE would normally cause a different, undesired execution plan. With CURSOR_SHARING=SIMILAR, Oracle determines which literals are "safe" for substitution with bind variables. This will result in some SQL not being shared in an attempt to provide a more efficient execution plan.
Muqthar Ahmed
DBA
-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Juan Cachito Reyes Pacheco
Sent: Thursday, April 29, 2004 6:03 PM
To: oracle-l_at_freelists.org
Subject: Re: Configure SDU and TDU parameters to improve Performance
Because the values 'SIMILAR' and 'FORCE' are temporary values
(even when you set for all the eternity) to fix binding problems immediatly.
They are specially where developers forgot to bind variables in c++,
jva,visual basic, etc. because oracle developer
binds automatically.
'SIMILAR' and 'FORCE' could cause unwanted results. give a check to the
documentation.
Juan Carlos Reyes Pacheco
OCP
Database 9.2 Standard Edition
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