Hi all I'm doing some tests for 12c new feature. I knew you guys are all experts willing to learn the new technology so I hope someone can answer my question even 12c is just released several days ago. 1. Can I set a PDB open automatically when the CDB is opened? 2. Is there a view that showed all the databases (including CDB and all the PDBs) information? like V$DATABASES for all the databases. 3. When will the ORA-24543 should occurred? Yesterday I tried to using "startup" to open the PDB, I got ORA-24543 error. SQL> startup ORA-24543: instance startup OR shutdown NOT allowed IN pluggable DATABASE Today I tried again, it worked. What I modified is enable the multi-threaded database mode by setting threaded_execution=TRUE. Does it related? SQL> SHOW USER USER IS "SYS" SQL> startup Pluggable DATABASE opened. SQL> SQL> SHOW con_name CON_NAME ------------------------------ PDBTEST -- Kamus <kamusis@xxxxxxxxx> Visit my blog for more : http://www.dbform.com Join ACOUG: http://www.acoug.org -- //www.freelists.org/webpage/oracle-l