7 Replies Latest reply on Sep 2, 2013 2:03 PM by 1013008

    Oracle 12c multi-tenanacy and ORA-1555 snapshot too old error


      Currently I have databases in Oracle 10g and Oracle 11g which sometimes give above error despite a large undo tablepsace (24G) and large  undo_retenetion_time (1 day). My export backups run for 4 hours and then fail with this error. I cannot do consistent export backups at all when users are running the system. Only when users are off, export backups are successful.


      Now in Oracle 12c multi-tenant database where several pluggable databases will share same undo table (because undo and redo have to be shared for all the pluggable databases

      in a container database), won't this problem get worse because different applications connecting to different pluggable databases can give this error which will affect everyone?