RE: Getting multiple explain plans for 1 sql statement

  • From: "Bobak, Mark" <Mark.Bobak@xxxxxxxxxxxxxxx>
  • To: <ryan_gaffuri@xxxxxxxxxxx>, <Brandon.Allen@xxxxxxxxxxx>, <oracle-l@xxxxxxxxxxxxx>
  • Date: Fri, 29 Sep 2006 17:36:40 -0400

One common occurrance which would cause that would be two different
users executing the identical SQL, but resolving to two different
For example:
select '1' into :x from my_tab where rownum=1;
if USER1 and USER2 each have their own table called my_tab.
There are lots of other reasons.  As Brandon (I think it was Brandon)
mentioned previously, check V$SQL_SHARED_CURSOR, and check the
documentation for the meaning of some of the columns in
Hope that helps,

Mark J. Bobak 
Senior Oracle Architect 
ProQuest Information & Learning 

For a successful technology, reality must take precedence over public
relations, for Nature cannot be fooled.  --Richard P. Feynman, 1918-1988



From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of
Sent: Friday, September 29, 2006 5:34 PM
To: Brandon.Allen@xxxxxxxxxxx; Allen, Brandon; oracle-l@xxxxxxxxxxxxx
Cc: Allen, Brandon
Subject: RE: Getting multiple explain plans for 1 sql statement

why would I spawn child cursors with different execution plans for the
exact same query with bind variables with the same plan_hash_value? 

        -------------- Original message -------------- 
        From: "Allen, Brandon" <Brandon.Allen@xxxxxxxxxxx> 
        I forgot to mention - there could also be different explain
plans for different child cursors of the same hash_value - check the
"child_number" column, and then check v$sql_shared_cursor to get an idea
of why there are multiple children.


                From: Allen, Brandon 
                Sent: Friday, September 29, 2006 10:54 AM
                To: 'ryan_gaffuri@xxxxxxxxxxx'; oracle-l@xxxxxxxxxxxxx
                Subject: RE: Getting multiple explain plans for 1 sql
                It's normal to have multiple rows in v$sql_plan for a
given hash_value - each row represents a single step of the explain
plan.  Do both rows have the same plan_hash_value?

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