As a suggestion for 5.0 having a scripted DB migration system would make upgrading much easier.

Something like what Asterisk now uses (Alembic https://pypi.python.org/pypi/alembic) would be ideal, as it works in a DB agnostic manner and you would just have to ensure that there is a driver for the DB you wish to use.

That way you would just update the definition script and select the target when you run the updater, and would allow kamailio a greater choice in backing DB’s as once the script is written assuming a driver is available for you RDBMS the schema would be successfully ported.

This would do away with maintaining separate MySQL, Postgres, Oracle, MSSQL scripts as well.

The only issue I can think with a system like this is in the situation where hardcoded SQL strings are in the source and use a RDBMS specific function as that could cause some “fun” in debugging…