ORA-30012: undo tablespace ‘UNDOTBS’ does not exist or of wrong type.
the undo_tablespace does not exist or is not of type undo (i.e. the contents
column of dba_tablespaces does not show ‘undo’ for this tablespace).
1. set undo_management=MANUAL in your init file.
2. connect “/ as sysdba” and startup the database using this init
file (if not it will use the SPFILE by default), e.g.:
3. drop the (‘undo’) tablespace if you wrongly created one without actually
4. create a new undo tablespace, e.g.:
datafile ‘/DB1/undotbs01.dbf’ size 1M reuse;
5. shutdown the database
6. change UNDO_MANAGEMENT=AUTO in your init file and set
UNDO_TABLESPACE=UNDOTBS (or whatever name you specified during the undo
7. connect “/ as sysdba” and startup the database using this init file
(as in step 2).
Now the database will open using the new undo tablespace and it would have
created new undo segments in this tablespace.