Sometimes at the first installation, we don’t care about the size of UNDO Tablespace. We just create it with maximum extensible unlimited size. So there’s one big data file with a big I/O since write-read process only on that file. This article I wrote for give you a solution how to replace an UNDO Tablespace with a big datafile with a new UNDO Tablespace with several tiny datafiles.
- Check the UNDO setting in the database :
SQL> show parameter undo NAME TYPE VALUE ------------------------------------ ----------- -------------------- undo_management string AUTO undo_retention integer 10800 undo_tablespace string UNDOTBS1