While tuning a SQL statement, the SQL Tuning Advisor finds an existing SQL profile for the statement that has stale statistics available.
What would the optimizer do in this situation?
A. It updates the existing SQL profiles with current statistics.
B. It makes the statistics information available to GATHER_STATS_JOB.
C. It initiates the statistics collection process by running GATHER_STATS_JOB.
D. It logs a warning message in the alert log so that the DBA can perform statistics collection manually.
操作代表由模块执行的作业。 例如， DBMS_SCHEDULER 模块可以运行 GATHER_STATS_JOB 操作来收集所有数据库对象的统计信息。 如果单个操作正在使用大部分等待时间，那么您应该调查它。