标签：ati art data info monitor start for answer call
Which two are true about Optimizer Statistics?A)They are gathered by the Manageability Monitor(MMON) background process.
B)They can be gathered by executing the PL/SQL procedures in the DBMS_STATES package.
C)They do not persist across instance restarts.
D)They can be used to determine the events on which a database instance waited.
E)They provide information to the Optimizer so that it can determine optimal execution plans for SQL statements.
F)They are automatically updated when DDL statements execute.
Answer: BE
标签：ati art data info monitor start for answer call
原文地址：https://blog.51cto.com/13854012/2424719
