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
objects.
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$SQL_SHARED_CURSOR, and check the
documentation for the meaning of some of the columns in
V$SQL_SHARED_CURSOR.
Hope that helps,
-Mark
--
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
ryan_gaffuri@xxxxxxxxxxx
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$sql_shared_cursor to get an idea
of why there are multiple children.
________________________________
From: Allen, Brandon
Sent: Friday, September 29, 2006 10:54 AM
To: 'ryan_gaffuri@xxxxxxxxxxx'; oracle-l@xxxxxxxxxxxxx
Subject: RE: Getting multiple explain plans for 1 sql
statement
It's normal to have multiple rows in v$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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