7 Replies Latest reply: Nov 11, 2012 9:45 PM by Hemant K Chitale RSS

    RMAN and ORA-01555 error

    Vorlon1
      Using RMAN to export a set of tables with consistency set to default (N).
      On READONLY tablespace.
      Getting ORA-01555. Why? Did I mention this is a READONLY tablespace? With NO CONSISTENCY!
      What is the need to use any UNDO at all?
        • 1. Re: RMAN and ORA-01555 error
          mseberg
          It is an interesting question how Oracle manages the undo for read-only.

          I might look at :

          ORA-1555 Using Automatic Undo Management - How to troubleshoot [ID 389554.1]

          or

          http://download.oracle.com/docs/cd/B28359_01/server.111/b28310/undo002.htm#BJFFIACJ


          ORA-01555 "Snapshot too old" - Detailed Explanation [ID 40689.1]

          http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::p11_question_id:1441804355350

          Best Regards

          mseberg

          It is possible
          using target database control file instead of recovery catalog
          RMAN-00571: ===========================================================
          RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
          RMAN-00571: ===========================================================
          RMAN-03002: failure of list command at 02/24/2011 14:24:42
          ORA-01555: snapshot too old: rollback segment number 20 with name "_SYSSMU20_328
          6862503$" too small
          RMAN-06031: could not translate database keyword
          ORA-01555  Snapshot too old


          ORA-01555: snapshot too old


          h3. Would forget the why and fix the issue

          increase size of UNDOTBS1

          Edited by: mseberg on Nov 9, 2012 7:21 AM
          • 2. Re: RMAN and ORA-01555 error
            Vorlon1
            Thanks for the reply, but these do not speak to why we need undo with a readonly tablespace.
            Absolutely no DML changing the data...
            The asktom reference below talks about read/write operations as well...
            Once a table/tablespace is READONLY, why is UNDO even a part of the discussion?
            • 3. Re: RMAN and ORA-01555 error
              tychos
              Hi Vorlon1,
              Using RMAN to export a set of tables with consistency set to default (N).
              Or Oracle recently changed functionality of rman or you are mixing up things here.
              I guess you have question for the data pump forum (or export/import forum) and not the rman forum.
              Regards,
              Tycho
              • 4. Re: RMAN and ORA-01555 error
                Vorlon1
                Perhaps, but I think that this question deals with 1) the database itself, and 2) RMAN.
                My point in mentioning consistency is to highlight that I was trying to exclude even that as a possible cause. Even though no DML is changing data (readonly tablespace) I am EXPLICITLY telling the db I don't care about that either...
                • 5. Re: RMAN and ORA-01555 error
                  Vorlon1
                  mseberg :Don't you agree that knowing why is important?

                  Edited by: Vorlon1 on Nov 9, 2012 5:31 AM
                  • 6. Re: RMAN and ORA-01555 error
                    tychos
                    Hi Vorlon1,
                    Well for the matter of consistency this only counts for consistency between tables in you export set not the data per exported table this still needs to be consistent.
                    Rgds,
                    Tycho
                    • 7. Re: RMAN and ORA-01555 error
                      Hemant K Chitale
                      Using RMAN to export a set of tables with consistency set to default (N).
                      Could you show us what exactly you are doing ? The command line ?


                      An ORA-1555 may also appear against the data dictionary which the export is attempting to read from.


                      Hemant K Chitale