While deploying a new application module, the software vendor ships the application software along with
appropriate SQL plan baselines for the new SQLs being introduced. Which two statements describe the
consequences? (Choose two.)
A.
The plan baselines can be evolved over time to produce better performance.
B.
The newly generated plans are directly placed into the SQL plan baseline without being verified.
C.
The new SQL statements initially run with the plans that are known to produce good performance under
standard test configuration.
D.
The optimizer does not generate new plans for the SQL statements for which the SQL plan baseline has
been imported.
Explanation:
Purpose of SQL Plan Baselines
Common scenarios where SQL plan management can improve or preserve SQL performance include:
A database upgrade that installs a new optimizer version usually results in plan changes for a small percentage
of SQL statements. Most of these plan changes result in either no performance change or improvement.
However, some plan changes may cause performance regressions. SQL plan baselines significantly minimize
potential regressions resulting from an upgrade.
Ongoing system and data changes can impact plans for some SQL statements, potentially causing
performance regressions. SQL plan baselines help minimize performance regressions and stabilize SQL
performance.
Deployment of new application modules means introducing new SQL statements into the database. The
application software may use appropriate SQL execution plans developed in a standard test configuration for
the new statements. If the system configuration is significantly different from the test configuration, then the
database can evolve SQL plan baselines over time to produce better performance.