Unplug a Pluggable Database (PDB) Manually

Unplug a Pluggable Database (PDB) Manually

Before attempting to unplug a PDB, you must make sure it is closed. To unplug the database use the ALTER PLUGGABLE DATABASE command with the UNPLUG INTO clause to specify the location of the XML metadata file.

ALTER PLUGGABLE DATABASE pdb2 CLOSE;

ALTER PLUGGABLE DATABASE pdb2 UNPLUG INTO '/u01/app/oracle/oradata/cdb1/pdb2/pdb2.xml';


The pluggable database is still present, but you shouldn't open it until the metadata file and all the datafiles are copied somewhere safe.

SELECT name, open_mode
FROM   v$pdbs
ORDER BY name;

NAME       OPEN_MODE
------------------------------ ----------
PDB$SEED       READ ONLY
PDB1       MOUNTED
PDB2       MOUNTED
PDB3       READ WRITE

SQL>

You can delete the PDB, choosing to keep the files on the file system.

DROP PLUGGABLE DATABASE pdb2 KEEP DATAFILES;


SELECT name, open_mode
FROM   v$pdbs
ORDER BY name;

NAME       OPEN_MODE
------------------------------ ----------
PDB$SEED       READ ONLY
PDB1       MOUNTED
PDB3       READ WRITE

SQL>

Plugin a Pluggable Database (PDB) Manually

Plugging in a PDB into the CDB is similar to creating a new PDB. First check the PBD is compatible with the CDB by calling the DBMS_PDB.CHECK_PLUG_COMPATIBILITY function, passing in the XML metadata file and the name of the PDB you want to create using it.

SET SERVEROUTPUT ON
DECLARE
  l_result BOOLEAN;
BEGIN
  l_result := DBMS_PDB.check_plug_compatibility(
                pdb_descr_file => '/u01/app/oracle/oradata/cdb1/pdb2/pdb2.xml',
                pdb_name       => 'pdb2');

  IF l_result THEN
    DBMS_OUTPUT.PUT_LINE('compatible');
  ELSE
    DBMS_OUTPUT.PUT_LINE('incompatible');
  END IF;
END;
/
compatible

PL/SQL procedure successfully completed.

SQL>
If the PDB is not compatible, violations are listed in the PDB_PLUG_IN_VIOLATIONS view. If the PDB is compatible, create a new PDB using it as the source. If we were creating it with a new name we might do something like this.

CREATE PLUGGABLE DATABASE pdb5 USING '/u01/app/oracle/oradata/cdb1/pdb2/pdb2.xml'
  FILE_NAME_CONVERT=('/u01/app/oracle/oradata/cdb1/pdb2/','/u01/app/oracle/oradata/cdb1/pdb5/');
Instead, we want to plug the database back into the same container, so we don't need to copy the files or recreate the temp file, so we can do the following.

CREATE PLUGGABLE DATABASE pdb2 USING '/u01/app/oracle/oradata/cdb1/pdb2/pdb2.xml'
  NOCOPY
  TEMPFILE REUSE;

ALTER PLUGGABLE DATABASE pdb2 OPEN READ WRITE;

SELECT name, open_mode
FROM   v$pdbs
ORDER BY name;

NAME       OPEN_MODE
------------------------------ ----------
PDB$SEED       READ ONLY
PDB1       MOUNTED
PDB2       READ WRITE
PDB3       READ WRITE

SQL>