RETENTION NOGUARANTEE

How to Resolve ORA-01555 UNDO_RETENTION

by Ed Chen
April 8, 2016December 11, 2022

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 »

UNDO_RETENTION, How and Why

by Ed Chen
April 7, 2016December 11, 2022

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 »

How to Resolve ORA-30036 UNABLE TO EXTEND SEGMENT BY 8 IN UNDO TABLESPACE 'UNDOTBS1'

by Ed Chen
October 19, 2012December 11, 2022

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 »