With the release of Oracle 12c and later enhancements in Oracle 18c and 19c, hot cloning of a Pluggable Database (PDB) has become a powerful feature for DBAs. Hot cloning allows you to clone a PDB while it’s open in read/write mode, without needing to quiesce the source PDB.

This is especially useful for:

• Development/Test provisioning
• Application environment refresh
• Backup/recovery strategy validation

Let’s walk through how to perform hot cloning in Oracle 19c.

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Prerequisites

Before you begin, ensure the following:

1. You’re using Oracle 18c or higher (we’re using 19c).
2. Source PDB is in read/write mode.
3. You have local undo mode enabled.
4. You have the required CREATE PLUGGABLE DATABASE privilege.
5. Target CDB (Container Database) has sufficient space.

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🔧 Environment

Parameter	Value
Source CDB	CDB1
Source PDB	PDB1
Target CDB (same)	CDB1
New Cloned PDB Name	PDB1_CLONE
Oracle Version	19c (19.14 tested)

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Step-by-Step: Hot Cloning PDB in Oracle 19c

Step 1: Connect to CDB as SYSDBA

sys@cdb1 as sysdba

Step 2: Open Source PDB in Read/Write Mode (if not already)

ALTER PLUGGABLE DATABASE pdb1 OPEN READ WRITE;

Step 3: Clone the PDB While It’s Open

CREATE PLUGGABLE DATABASE pdb1_clone 
FROM pdb1 
FILE_NAME_CONVERT = ('/u01/app/oracle/oradata/CDB1/pdb1/', 
                     '/u01/app/oracle/oradata/CDB1/pdb1_clone/');

Note1:

• FILE_NAME_CONVERT ensures datafiles are copied to a new location.
• This command hot clones PDB1 even though it’s in use.

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Step 4: Open the Cloned PDB

ALTER PLUGGABLE DATABASE pdb1_clone OPEN;

Step 5: Optional – Save it in pdb$seed for future clones

If this PDB will be used for future template-based clones:

ALTER PLUGGABLE DATABASE pdb1_clone SAVE STATE;

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Check the Cloning Result

Run:

SELECT pdb_name, status FROM dba_pdbs;

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Notes & Best Practices

• Ensure adequate storage before cloning.
• Use DBMS_PDB.DESCRIBE if cloning across different CDBs.
• Consider using refreshable clones for continuous syncs.
• Hot cloning works only in local undo mode (UNDO_MODE = LOCAL in CDB$ROOT).

Check:

SELECT property_name, property_value 
FROM database_properties 
WHERE property_name = 'LOCAL_UNDO_ENABLED';

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Hot Clone Across CDBs

To hot clone across CDBs:

On source CDB:
BEGIN DBMS_PDB.DESCRIBE( pdb_descr_file => ‘/tmp/pdb1.xml’, pdb_name => ‘PDB1’); END; /

On target CDB:
REATE PLUGGABLE DATABASE pdb1_clone USING ‘/tmp/pdb1.xml’ FILE_NAME_CONVERT = (‘/CDB1/PDB1/’, ‘/CDB2/PDB1_CLONE/’) COPY;