[oracle@localhost ~]$ oerr ora 1555 01555, 00000, "snapshot too old: rollback segment number %s with name \"%s\" 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 undo_retention // setting. Otherwise, use larger rollback segments [oracle@localhost ~]$ oerr ora 0001 00001, 00000, "unique constraint (%s.%s) violated" // *Cause: An UPDATE or INSERT statement attempted to insert a duplicate key. // For Trusted Oracle configured in DBMS MAC mode, you may see // this message if a duplicate entry exists at a different level. // *Action: Either remove the unique restriction or do not insert the key. [oracle@localhost ~]$