Downgrading Replication Agent for Oracle

You can downgrade Replication Agent for Oracle from version 15.7.1 to version 15.2 ESD #2 or later.

You may need to downgrade Replication Agent if the upgrade process fails or if replication fails after an upgrade. Replication may fail when new features fail to function as expected or if there are changes to:

DDL and how it is handled by Replication Agent
The content or structure of the Replication Agent System Database (RASD)

If you are using any new features from Replication Agent 15.7.1, you cannot downgrade. For a list of the new features for Replication Agent 15.7.1, see the Replication Agent New Features.

Replication Agent 15.7.1 must be installed on the same platform on which the primary Oracle server is running.

Change to the Replication Agent 15.7.1 bin directory:
- On UNIX:
  cd $SYBASE/RAX-15_5/bin
- On Windows:
  cd %SYBASE%\RAX-15_5\bin
The Replication Agent directory name for release 15.5 and later is RAX-15_5.
Run the ra_downgrade command at the Replication Agent instance from which you are downgrading (the current version):
```
ra_downgrade
```
The ra_downgrade command extracts the contents of the Replication Agent System Database (RASD) to a file named timestamp.export, where timestamp is a timestamp taken at the moment ra_downgrade was invoked. This file is located in the import subdirectory under the directory specified by the rasd_backup_dir configuration parameter of the Replication Agent instance to which you are downgrading (the earlier version). The absolute path to this file is returned if ra_downgrade executes successfully.

Note: The ra_downgrade_prepare and ra_downgrade_accept commands are deprecated as of Replication Agent 15.7.1.
Complete the downgrade by running the ra_downgrade_accept command at the Replication Agent instance to which you are downgrading (the earlier version):
```
ra_downgrade_accept timestamp.export
```
where timestamp.export is the file to which the ra_downgrade command extracted RASD contents.

If the ra_downgrade_accept command executes successfully, Replication Agent shuts down.
Start the Replication Agent instance to which you have downgraded (the earlier version), and resume replication:
```
resume purge
```
The purge keyword is needed here to purge data from the Replication Server inbound queue for the connection to which this Replication Agent is connected. Purging prevents any duplicate records from being created in Replication Server as a result of the change in OQID formats between the earlier and later versions of Replication Agent.