18c Database : Refreshable PDB’s Switchover

In 12c, we can have refreshable PDB from one PDB to another PDB via database link.

--Manual Refresh

CREATE PLUGGABLE DATABASE pdb_ref FROM pdb1@pdb_link REFRESH MODE MANUAL;

-- Automatically refresh ever 60 minutes.

CREATE PLUGGABLE DATABASE pdb_ref FROM pdb1@pdb_link REFRESH MODE EVERY 60 MINUTES;

In 18c, this is extended and we can switchover the primary and clone DB act as source and vice versa using

ALTER SESSION SET CONTAINER = pdb_ref;
ALTER PLUGGABLE DATABASE REFRESH MODE MANUAL FROM pdb1@pdb_link SWITCHOVER;

Now with above alter statement, pdb_ref will be marked as source and pdb1 will be marked as clone.

Now, you must open the PDB1 (source) as readonly and set refresh mode manual or set interval.

ALTER SESSION SET CONTAINER = pdb1

ALTER PLUGGABLE DATABASE OPEN READ ONLY;

ALTER PLUGGABLE DATABASE REFRESH MODE EVERY 10 MINUTES;

Then, you can log to the reference PDB which is actually a clone but currently the source PDB and do any DML which will eventually populates to PDB1

-Thanks

Suresh

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