OCP|052OCP最新题库解析系列-2

Posted 2020-12-02

2、Which two are true about Optimizer Statistics?
? A) They do not persist across Instance restarts.
? B) They are automatically updated when DDL statements
execute.
? C) They are gathered by the Manageability Monitor (MMON)
background process.
? D) They can be gathered by executing the PL/SQL procedures
in the DBMS_STATS package.
? E) They can be used to determine the events on which a
database instance waited.
? F) They provide Information to the Optimizer so that it can
determine optimal execution plans for SQL statements.
? Answer:DF