Truncate vs Delete
Truncate vs Delete Here I compare the differences between TRUNCATE and DELETE an entire table in the following chart. Question Truncate Table Delete From DDL… Read More »Truncate vs Delete
Undo
How to Resolve ORA-01555 UNDO_RETENTION
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
UNDO_RETENTION, How and Why
UNDO_RETENTION At times, you may find out or feel that UNDO_RETENTION is useless at all. Raising the number of seconds cannot resolve ORA-01555. This is… Read More »UNDO_RETENTION, How and Why
How to Resolve SMON: about to recover undo segment xx SMON: mark undo segment xx as available
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
How to Resolve ORA-01562: failed to extend rollback segment number
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