You are working on the 24X7 database with high transaction volume， to ensure faster instance recovery on your database you set the FAST_START_MTTR_TARGET initialization parameter to a very low value. What effect it will have on the database？（）

A.It is not possible to disable the primary key constraint.
B.It is possible to have more than one primary key constraint in a single table.
C.The primary key constraint can be referred by only one foreign key constraint.
D.The primary key constraint can be imposed by combining more than one column.
E.The non-deferrable primary key constraint creates an unique index on the primary key column if it is not already indexed.

A.use the external table population
B.use the Oracle Data Pump export and import utility
C.use the conventional path data load of SQL*Loader utility
D.use the direct path data load of Oracle export and import utility

A.The optimizer statistics are collected automatically.
B.Only the timed operating system （OS） statistics and plan execution statistics are collected.
C.The Oracle server dynamically generates the necessary statistics on tables as part of query optimization.
D.The snapshots for the Automatic Workload Repository （AWR） are not generated automatically. 
E.Snapshots cannot be collected manually by using DBMS_WORKLOAD_REPOSITORY PACKAGE.