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Oracle® Database 11g / 12c / 18c error codes ORA-01555: snapshot too old: rollback segment number [string] with name "[string]" too small
ORA-01555: snapshot too old: rollback segment number [string] with name "[string]" too small
Oracle Error Code: ORA-01555
Cause: rollback records needed by a reader for consistent read are overwritten by other writers
Action: If in Automatic Undo Management mode, increase undo_retention setting. Otherwise, use larger rollback segments