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