?? Cloning a Pluggable Database (PDB) in Oracle CDB: The Smart & Efficient Way!

As an Oracle Database Administrator (DBA), database cloning is one of the most common yet critical tasks, especially in migration, development, and testing scenarios. With Oracle Multitenant Architecture, cloning a Pluggable Database (PDB) has become smarter and more efficient. In this blog, I'll walk you through the best practices and commands to achieve a fast and efficient PDB clone in a Container Database (CDB) environment.

?? Why Clone a PDB?

Cloning a PDB is beneficial when you:

• Need a copy of the database for development and testing
• Plan to migrate a database to another environment
• Want to create a backup instance without disrupting the live database
• Need to quickly provision a fresh database instance for a new project

With Oracle 19c and later, the cloning process has become more streamlined and requires minimal downtime.

?? Latest & Smartest Ways to Clone a PDB ??

There are several methods to clone a PDB, but let's focus on the most efficient techniques:

1?? Cloning a PDB Locally (Cold Clone - No Open Users Required)

Use this method when the PDB can be closed before cloning.

ALTER PLUGGABLE DATABASE source_pdb CLOSE;        

CREATE PLUGGABLE DATABASE clone_pdb FROM source_pdb;        

ALTER PLUGGABLE DATABASE clone_pdb OPEN;                                                                                             

?? This method ensures a clean and quick clone with minimal resources.

2?? Cloning a PDB While Keeping It Open (Hot Clone - Minimal Downtime)

From Oracle 12.2 onwards, you can clone a PDB while it's open in read-only mode, ensuring minimal downtime for active applications.

ALTER PLUGGABLE DATABASE source_pdb OPEN READ ONLY;        

CREATE PLUGGABLE DATABASE clone_pdb FROM source_pdb;        

ALTER PLUGGABLE DATABASE clone_pdb OPEN;        

?? This technique is useful for production environments where downtime is not an option.

3?? Remote PDB Cloning (Across Different CDBs - On-Premise or Cloud)

This is useful for cross-environment migrations, especially when moving databases to AWS RDS, Oracle Cloud, or hybrid environments.

CREATE PLUGGABLE DATABASE remote_clone_pdb FROM source_pdb@remote_link;        

ALTER PLUGGABLE DATABASE remote_clone_pdb OPEN;        

?? Make sure your database link (DB Link) is properly configured to enable remote cloning.

4?? Snapshot Copy Cloning (Super-Fast, Uses Storage Snapshots)

Introduced in Oracle 12.2, this method allows cloning instantly using a snapshot copy. The clone PDB shares storage with the source, making it extremely fast!

CREATE PLUGGABLE DATABASE clone_pdb FROM source_pdb SNAPSHOT COPY;        

ALTER PLUGGABLE DATABASE clone_pdb OPEN;        

?? This technique is the fastest but requires Oracle ACFS, ZFS, or an ASM File System with Thin Provisioning.

?? Best Practices for Efficient PDB Cloning

? Use the right method based on your downtime tolerance and infrastructure.

? Optimize storage – Use snapshot cloning whenever possible.

? Monitor performance post-cloning to ensure smooth operations.

? Automate the cloning process using scripts for large-scale deployments.

?? Final Thoughts

Cloning a Pluggable Database (PDB) is a powerful feature of Oracle's Multitenant architecture that simplifies database management and deployment. Whether you’re working in on-premises environments or cloud-based solutions like AWS RDS or Oracle Cloud, choosing the right cloning technique can save time and resources.

?? Which method do you prefer for cloning PDBs? Let’s discuss in the comments! ??

#OracleDBA #DatabaseCloning #PDB #Multitenant #CloudMigration #AWS