You have statistics collected for some selected tables. Your requirement is that the statistics for the
tables and all dependent indexes must not be overwritten by further statistics collection until a
certain point of time. How would you achieve this?
A.
Lock statistics for the tables.
B.
Change STALE_PERCENT to zero for the tables.
C.
Set the TIMED_STATISTICS parameter to TRUE.
D.
Set the STATISTICS_LEVEL parameter to BASIC.
E.
Set the OPTIMIZER_USE_PENDING parameter statistics to TRUE.
You can maintain optimizer statistics manually using the DBMS_STATS package. For example, you can save and restore copies of statistics.
You can export statistics from one database and import those statistics into another database.
You can also lock statistics to prevent them from changing.
http://docs.oracle.com/cd/E11882_01/server.112/e41573/stats.htm#PFGRF94712
You can also lock statistics to prevent them from changing.
STAT must NOT be OVERWRITTEN. SO LOCK it.