5 Database Administration

Rollback Segment

1Check the message log for ORA-04031. The text portion of this message indicates there is not enough shared memory space.

2Access the /oracle/dbs/initA.ora file.

3Place a pound sign (#) in front of the value shared_pool_size=3500000.

4Remove the pound sign (#) from the front of the value shared_pool_size=6000000.

5Save and exit the file.

6Enter /oracle/bin/ior c to stop the database system.

7Enter /oracle/bin/ior w to start the database system.

Rollback Segment

A rollback segment is a storage buffer that records actions that can be undone under certain circumstances. The rollback segment grows as needed as long as there is available space in the database. However, the rollback segment does not automatically decrease in size, and some ORACLE operations can cause the rollback segment to grow dramatically. Consequently, you might want to restore the rollback segment to the original size by first eliminating it, and then recreating it.

The installation of the Base ORACLE software package creates one rollback segment called R1.

UCS 1000 R4.2 Administration 585-313-507

Issue 3 April 2000 224