SQL> select N.Name, /* rollback segment name */ 2 S.OptSize /* rollback segment OPTIMAL size */ 3 from V$ROLLNAME N, V$ROLLSTAT S 4 where N.USN=S.USN; NAME OPTSIZE ------------------------------ ---------- SYSTEM _SYSSMU1$ _SYSSMU2$ _SYSSMU3$ _SYSSMU4$ _SYSSMU5$ _SYSSMU6$ _SYSSMU7$ _SYSSMU8$ _SYSSMU9$ _SYSSMU10$ SQL>