If two Applications Manager instances need to be merged, it is not possible to do so via sql or via database backend.
Below is recommendation to to merge Applications Manager instances. Please note that this may not cover every situation or environment and thorough testing should be done and performed on a non prod environment first.
Applications Manager 9.x.x
Things to note:
Steps:
Again, note that the described steps should be considered a general overview only and it is highly recommend testing this out in a non prod environment first.