RE: Any way to invalidate/flush a single cursor

  • From: Tanel Poder <tanel.poder.003@xxxxxxx>
  • To: Brandon.Allen@xxxxxxxxxxx, "'ORACLE-L'" <oracle-l@xxxxxxxxxxxxx>
  • Date: Tue, 22 Aug 2006 16:29:53 +0800

One option is to create view as select * from table and write your test
query against this view.
Then verify that you get the same execution plan against this view as
against the table directly.
Then just recompile that view when you want to invalidate your cursor.
Btw, if you want to invalidate all cursors dependent on a table you could
just add a comment to the table rather than reanalyzing it.
There's one more way to selectively force hard parsing on already cached
cursors, but I'd like to document this in a paper along its implications
before publishing it..


From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of Allen, Brandon
Sent: Tuesday, August 22, 2006 05:30
Subject: Any way to invalidate/flush a single cursor

Does anyone know of a way to invalidate or completely flush a single cursor?
I'm doing some performance testing of queries that are having trouble with
bind variable peeking and sharing plans between executions with drastically
different bind values, so I need to invalidate the cursor in between
executions in order to test the explain plans of different bind variables.
Is there any more focused approach than gathering stats or issuing grants on
one of the query's tables?  That works, but of course invalidates all other
queries referencing the table.
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