Why have one database when you can have two? Exactly!

In this post I will show what is needed to clone a pluggable database from a remote CDB over a database link. I will also include some steps to take in case your are working with a standby. This procedure should work without the standby getting out of sync.

If you just want to clone a pluggable database within the same CDB, you can just do the following:

SQL> create pluggable database <NEW_PDB_NAME> from <SOURCE_PDB>;

Create a database link to the remote CDB

Lets write down some steps and number them, just for the sake of it. Lets go

1. Create a user in the remote CDB (so a common user) and grant the following privileges: connect, sysoper. With container=all
2. Its a good thing to open the remote PDB in read only mode.
3. If you cant just close and reopend the PDB because its a production database. You can also just clone the PDB within the same PDB, as showed before, and then use the clonend PDB in read only mode to close.
4. Create the database link:

SQL> create database link CLONE_PDB_LINK connect to <USER> identified by &source_password using '<LISTENER>:1521/<SERVICE>';

Just to be sure, test the database link:

SQL> select * from dual@CLONE_PDB_LINK;

Just in case you have a standby

If you do have a standby, you can define this database link. This way the standby will go out and get the database files from the remote CDB. This makes that the standby will not go out of sync and prevents any RMAN work.

Specify the parameter as follows:

SQL> alter system set STANDBY_PDB_SOURCE_FILE_DBLINK=CLONE_PDB_LINK scope=both sid='*';

Now then, lets clone

Execute the following to clone the PDB over the database link:

SQL> create pluggable database <NEW_PDB_NAME> from <REMOTE_PDB>@CLONE_PDB_LINK standbys=ALL;

After a while, your PDB will be cloned.

Want to watch progress on your standby?

It takes a while for the standby to receive the data files. You can use the following query to hceck the progress:

SQL> select p.name CONTAINER, d.name DATAFILE, d.status STATUS ,d.file# FILEID 
from v$datafile d 
left join v$containers p on d.con_id=p.con_id 
where p.name = '<NEW_PDB_NAME>';

Just give it some time. The status will go from RECOVER to UNUSABLE and to ONLINE.

Dont forget to add some temp files to the standby and enjoy your new, old PDB!