The OP said that the plan *hash value* didn't change, but since the
predicate placement doesn't affect the hash value, it's worth confirming on
which plan lines the predicates are applied.
You'd just make sure that the predicates in both plans (with the same plan
hash value) are on the same lines, "operation id"-s as highlighted below:
SELECT SUM(order_total) FROM soe.orders WHERE order_id = 5
Plan hash value: 1761615243
-------------------------------------------------------------------
| Id | Operation | Name | Starts | E-Rows |
-------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | |
| 1 | SORT AGGREGATE | | 1 | 1 |
| 2 | TABLE ACCESS BY INDEX ROWID| ORDERS | 1 | 1 |
|* 3 | INDEX UNIQUE SCAN | ORDER_PK | 1 | 1 |
-------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
* 3 - access("ORDER_ID"=5)*
Tanel.
On Thu, Oct 31, 2019 at 10:39 PM Chris Taylor <
christopherdtaylor1994@xxxxxxxxx> wrote:
But wouldn't that show up in the plan? I must be missing something.
How can you tell by examining the predicate section where the filtering is
occurring?
Chris
On Thu, Oct 31, 2019, 8:35 PM Tanel Poder <tanel@xxxxxxxxxxxxxx> wrote:
Even if the plan hash values are the same, go still ahead and compare the
predicate sections of the good vs bad child cursors.
Predicate existence (or placement) is not part of the plan hash value -
so how early you're filtering the rows may differ.
Tanel Poder
https://blog.tanelpoder.com/seminar
On Thu, Oct 31, 2019 at 2:03 PM Jeffrey Beckstrom <jbeckstrom@xxxxxxxxx>
wrote:
I have a couple of SQL statements that have multiple child cursors. Each
child cursor has the same plan hash value. The plans all show "this is an
adaptive plan (rows marked '-' are inactive)". The difference is that on
the "good" child cursor, the plan also shows "statistics feedback used for
this statement". Since all of the plans have the same plan hash value, I
can not use baselines (or can I).
Any suggestions on how to force Oracle to always use the "good" child
cursor.
Jeffrey Beckstrom
Lead Database Administrator
Information Technology Department
Greater Cleveland Regional Transit Authority
1240 W. 6th Street
Cleveland, Ohio 44113
