How to create a multimaster database replication

I recommend you completely read the official guide Oracle 9i Advanced Replication.pdf before proceeding with this document

 

In this case I recommend using the GUI Enterprise Manager (seems to work well),  remember that you need the Enterprise Edition

We suppose you have an instance and db called "p1" and you want to replicate to an instance and db "p2"

I recommend the databases use the same character set, after that ensure your instances are using the correct parameters, please check parameters for replication

This method require you to take now an export  on p1, stop activity on p1, import on p2, perform a logical test on p2 to ensure it is a perfect copy of p1 

Obviously the GUI is FULL of  bugs and tests missing, we will now follow the wizard just to create the user REPADMIN and create the db link

Go to "Distributed-Advanced Replication-Multimaster Replication" and launch "Setup Master Sites"

    1- Add the instances needed

    2-You may confirm for REPADMIN and go on until end with defaults

    3-One minute is a good choice to avoid many concurrence error logs

 

After completed this task login to p1 as REPADMIN

Go to "Distributed-Advanced Replication-Multimaster Replication-Master Groups", right click to select "Create"

    GENERAL: We enter "REP1" and no connection qualifier

    MASTER SITES: Add p2, select use existing object, and DEselect copy row data

BUG WARNING: Be sure that "Master Sites - Master Definition Site" report the correct database link name, the bug is that sometime the domain is overriden with ORACLE.COM.US, in this case I had to rebuild the database

Now add any object you like, always ensure in the "Objects" pane that "Copy row data" is deselected because you performed an export

Be sure to manually select "No" for the "Copy Row Data" field in the "Objects" pane when adding new Table objects
You can manually force multimaster sync without waiting for the job, click "View Administrative Request" and press the "Apply" button
Remember to login from Enterprise Manager as REPADMIN, otherwise you will always see red the graph link between masters
Avoid sequences using

SELECT SYS_GUID() OID FROM DUAL;