HP R4.2 - Manual (Page 263)

5
Database Administration Rollback Segment
UCS 1000 R4.2 Administration 585-313-507 Issue 3 April 2000 224
1 Check the message log for ORA-04031. The text portion of this message
indicates there is not enough shared memory space.
2 Access the /oracle/dbs/initA.ora file.
3 Place a pound sign (#) in front of the value shared_pool_size=3500000 .
4 Remove the pound sign (#) from the front of the value
shared_pool_size=6000000 .
5 Save and exit the file.
6 Enter /oracle/bin/ior c to stop the database system.
7 Enter /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.