SNAP_ID |
NUMBER |
NOT NULL |
Unique snapshot ID |
DBID |
NUMBER |
NOT NULL |
Database ID for the snapshot |
INSTANCE_NUMBER |
NUMBER |
NOT NULL |
Instance number for the snapshot |
USN |
NUMBER |
NOT NULL |
Rollback segment number |
EXTENTS |
NUMBER |
|
Number of extents in the rollback segment |
RSSIZE |
NUMBER |
|
Size (in bytes) of the rollback segment. This value differs from the value of the BYTES column of the DBA_SEGMENTS views by the number of bytes in one database block. |
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 decreased |
WRAPS |
NUMBER |
|
Number of times the rollback segment has wrapped |
EXTENDS |
NUMBER |
|
Number of times the rollback segment size has extended |
AVESHRINK |
NUMBER |
|
Average shrink size |
AVEACTIVE |
NUMBER |
|
Current size of active extents, averaged over time |