USN | 
NUMBER | 
Rollback segment number | 
LATCH | 
NUMBER | 
Latch for the rollback segment | 
EXTENTS | 
NUMBER | 
Number of extents in the rollback segment | 
RSSIZE | 
NUMBER | 
Size (in bytes) of the rollback segment. This value differs by the number of bytes in one database block from the value of the BYTES column of the *_SEGMENTS view.
See Also: Oracle Database Administrator's Guide 
 | 
WRITES | 
NUMBER | 
Number of bytes written to the rollback segment | 
XACTS | 
NUMBER | 
Number of active transactions | 
GETS | 
NUMBER | 
Number of header gets | 
WAITS | 
NUMBER | 
Number of header waits | 
OPTSIZE | 
NUMBER | 
Optimal size of the rollback segment | 
HWMSIZE | 
NUMBER | 
High watermark of the rollback segment size | 
SHRINKS | 
NUMBER | 
Number of times the size of a rollback segment decreases | 
WRAPS | 
NUMBER | 
Number of times rollback segment is wrapped | 
EXTENDS | 
NUMBER | 
Number of times rollback segment size is extended | 
AVESHRINK | 
NUMBER | 
Average shrink size | 
AVEACTIVE | 
NUMBER | 
Current size of active extents, averaged over time. | 
STATUS | 
VARCHAR2(15) | 
Rollback segment status:
- 
ONLINE 
 
- 
PENDING OFFLINE 
 
- 
OFFLINE 
 
- 
FULL 
 
 
 | 
CUREXT | 
NUMBER | 
Current extent | 
CURBLK | 
NUMBER | 
Current block |