donot confuse pdb$seed is the template to create new pluggable databases
we have only 1 pluggable database RED on container database and it is in mounted state
SQL> select name, open_mode from v$pdbs;
NAME OPEN_MODE
--------------- ----------
PDB$SEED READ ONLY
RED MOUNTED
command to open pluggable database 'RED'
SQL> alter pluggable database red open;
SQL> select name, open_mode from v$pdbs;
NAME OPEN_MODE
--------------- ----------
PDB$SEED READ ONLY
RED READ WRITE
command to close pluggable database RED on container database
SQL> alter pluggable database red close immediate;
SQL> select name, open_mode from v$pdbs;
NAME OPEN_MODE
--------------- ----------
PDB$SEED READ ONLY
RED MOUNTED
command to close all pluggable databases on container database
SQL> alter pluggable database all close immediate;
SQL> select name, open_mode from v$pdbs;
NAME OPEN_MODE
--------------- ----------
PDB$SEED READ ONLY
RED MOUNTED
command to open all pluggable databases on container database
SQL> alter pluggable database all open;
Pluggable database altered.
SQL> select name, open_mode from v$pdbs;
NAME OPEN_MODE
--------------- ----------
PDB$SEED READ ONLY
RED READ WRITE
Note: when ever we start container database, all of our pluggable databases are in mount state. we have to open them manually or we can place a trigger on container database which will open all pluggable databases after bouncing the database on the server
--Nikhil Tatineni--
--12c: Pluggable databases--
