 |
|
11g Cases for Automatic SQL Plan Management
Oracle 11g New Features Tips by Burleson
Consulting
June 29, 2008 |
Oracle 11g New Features Tips
Good candidate situations would
certainly be any upgrades of the Oracle 11g database system. Again,
use a testing system with changed
environment, possibly a Snapshot Standby Database, and run the
application for a representative period of time. During this period,
Automatic SQL Plan Management would be enabled and Oracle would
evolve the SQL Plan Baselines for our application.
After this evolution, it is possible to
use dbms_spm to create a staging table and then expdp
to EXPORT the captured baselines and import them into the production
system directly after upgrading. This would guarantee stable
execution plans from the very beginning. How this is done will be
shown in detail shortly.
Another scenario would be the
deployment of a new application. The application vendor would ship
well tuned plans in the form of exported SQL plan baselines together
with the application which could be imported after the application
was added to the database system. This would guarantee that the good
plans would be used right away from the very beginning. Oracle would
use new plans only if they were verified to not cause performance
degradation.
A variation of this case could be using
an 11g database as a testing system and IMPORT SQL Tuning Sets using
a staging table from a pre-11g database system. By
setting optimizer_features_enable to a pre-11g value, Oracle
finds the best execution plans for the workload on the 11g testing
system. After this, use the SQL Tuning set packed into a staging
table again and then import them back into the pre-11g database.
SQL Plan Management in OEM
The enterprise manager comes with an interface
for SQL plan management and offers full control of SQL plan
evolution.
This shows the link to SQL Plan Control for the
SMB in the Query Optimizer section of the SERVER pane. Also find the
SQL Profiles and SQL Patches.
