11 Replies Latest reply on Oct 5, 2012 11:47 AM by John Stegeman

    Ora-01555, snapshot too old: rollback segment number 2 with name "_SYSSMU1

      Oracle 10g,
      Im getting this error during execution of a query

      Autoextend is ON for the undo datafile

      There is 6 GB free space in the undo tablespace

      Earlier the value for undo_retention was 18000.

      I reset it using alter system set command to 25000.

      But it still gives the same error
      Please suggest on what could be the issue