Exam 1z0-053 topic 15 question 28 discussion

Actual exam question from Oracle's 1z0-053

Question #: 28
Topic #: 15

You perform the following activities during the database upgrade from Oracle Database 10g to Oracle Database 11g:
What is the reason for performing these activities?

A. to minimize plan regression due to the use of a new optimizer version
B. to completely avoid the use of new plans generated by a new optimizer version
C. to prevent plan capturing when the SQL statement is executed after the database upgrade
D. to keep the plan in the plan history so that it can be used when the older version of the optimizer is used

Show Suggested Answer

Suggested Answer: A 🗳️
15.1.1 Purpose of SQL Plan Baselines (Link)
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.

by thuthuysphn58 at April 4, 2025, 8:18 a.m.

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