Truncate vs Delete Entire Table
Here I compare the differences between TRUNCATE and DELETE an entire table in the following chart. Question Truncate Table Delete From DDL or DML? DDL… Read More »Truncate vs Delete Entire Table
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