Thursday, December 19, 2013

RULE lives on and on and on...

I’ve often said that Oracle will have an easier time getting rid of the IO costing model then Rule based optimizing.  Rule lives on in  Maybe in my life time I’ll see the day when RULE is gone, but not this day.   

C:\OP>sqlplus op/op

SQL*Plus: Release Production on Thu Dec 19 13:48:39 2013

Copyright (c) 1982, 2013, Oracle.  All rights reserved.

Last Successful login time: Thu Dec 19 2013 13:44:55 -05:00

Connected to:
Oracle Database 12c Enterprise Edition Release - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options

SQL> alter session set OPTIMIZER_MODE = rule;
SQL> @hxplan
Enter .sql file name (without extension): emp
Enter the display level (TYPICAL, ALL, BASIC, SERIAL) [TYPICAL]  :
Plan hash value: 1445457117

| Id  | Operation         | Name      |
|   0 | SELECT STATEMENT  |           |

Predicate Information (identified by operation id):

   1 - filter("FIRST_NAME"='David')

   - rule based optimizer used (consider using cbo)

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