-
Título
Compare client log shows error “ORA-01555: snapshot too old” -
Descripción
The following errors are observed in compare client log when compare fails:
declt 2019-10-09 15:44:49.755002 96483 2979432384 Oracle Error 1555: ORA-01555: snapshot too old: rollback segment number nn with name "<undo_segment_name> too small
.
.
declt 2019-10-09 15:44:49.791533 96483 2979432384 Error 1555 calling OCIStmtExecute (de_select_prepare_to_fetch,L1418)
declt 2019-10-09 15:44:49.794247 96483 2979432384 Error 1 calling de_select_prepare_to_fetch in de_batch_setup
-
Causa
The undo segment need to be resized due to a long running compare/repair. -
Resolución
Either resize (increase) the undo segment named in the error messages or run compare/repair at quiet times.
The error applies to both compare and repair.
Here is the explanation of the ORA-01555:
ORA-01555: snapshot too old: rollback segment number string with name "string" too small
Cause: Rollback records needed by a reader for consistent read are overwritten by other writers.
Action: If in Automatic Undo Management mode, increase the setting of UNDO_RETENTION. Otherwise, use larger rollback segments.