ORA-30012 Tried to restart a normal database after changing the default undo tablespace, but it failed with ORA-30012. SQL> startup ORACLE instance started. ... Database… Read More »How to Resolve ORA-30012: undo tablespace does not exist or of wrong type
ORA-01555 UNDO_RETENTION Let's see the error ORA-01555 UNDO_RETENTION first: Description ORA-01555: snapshot too old: rollback segment number string with name "string" too small Cause rollback… Read More »How to Resolve ORA-01555 UNDO_RETENTION
Repeated messages were found in the alert log after instance startup:...SMON: about to recover undo segment 32SMON: mark undo segment 32 as availableSMON: about to recover… Read More »How to Resolve SMON: about to recover undo segment xx SMON: mark undo segment xx as available
Found repeated errors in the alert log:...ORA-01562: failed to extend rollback segment number 96...It seemed that some transactions were doing DML, but they failed to… Read More »How to Resolve ORA-01562: failed to extend rollback segment number
ORA-30036 This error ORA-30036 could be very serious in a situation that is described below and may make users panic: One day, a DBA was… Read More »How to Resolve ORA-30036 UNABLE TO EXTEND SEGMENT BY 8 IN UNDO TABLESPACE 'UNDOTBS1'