Thursday, 27 August 2009

Performance Tuning - Question 049

V$ROLLSTAT can be used to determine?

A . The performance characteristics of all undo segments defined in the database.

B. The performance characteristics of all undo segments currently online in the database.

C . Only the STATUS of an undo segment is ONLINE or OFFLINE.

D . The performance characteristics of all manually configured rollback segments defined in the database only.

E . The performance characteristics of all manually managed redo segments defined in the database only.



Explanation:

Answer B: The V$ROLLSTAT view is used for either manually or automatically configured undo segments, but not both at the same time, because the database will only support one or the other. V$ROLLSTAT is limited to one row for each undo segment that is currently online.

No comments:

Post a Comment