Which method allows you to change the retention period for performance statistics in Oracle?

The correct method to change the retention period for performance statistics in Oracle is through the DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS procedure. This procedure specifically allows you to adjust how long the Automatic Workload Repository (AWR) retains performance statistics.

AWR is a crucial component for monitoring database performance, as it collects, processes, and maintains performance data. By using this procedure, database administrators can optimize the retention settings according to the needs of their environment and ensure that they have the necessary historical performance insights available for analysis.

The other options listed focus on different aspects of database performance and management. While DBMS_PERF_STATS.MODIFY_SETTINGS is related to performance statistics, it does not specifically target the retention period. DBMS_STATS.CHANGE_RETENTION_PERIOD is not a valid procedure for changing retention; instead, it focuses on gathering statistics for optimizer use. Lastly, DBMS_PERFORMANCE.RESET_STATS pertains to resetting performance statistics rather than modifying retention settings. Thus, the selection of DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS is the appropriate choice for this particular task.