Usually, we have separate undo tablespace for each instance in a RAC database. For example, UNDOTBS1 is for the first instance and UNDOTBS2 is for… Read More »PDB Local Undo for Each RAC Instance
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 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
The first purpose of using UNDO is for storing all uncommitted data in case we need to undo uncommitted data in rollback or after system… Read More »Oracle Undo Tablespace Usage