DbDiff is a simple command line application that identifies schema differences between databases. Unlike other tools in this space, it does not attempt to help you resolve differences.
Currently the tool uses the built in jdbc mechanisms for getting at databases metadata. This leaves us at the mercy of the underlying jdbc driver and not all of them seem to implement the full suite of methods. Also there is currently several elements of the database schema that are not exposed through an API. In most cases the underlying database provides access to the features through custom SQL.
So in the future we should use vendor specific SQL to get access to database features that we need to check. These currently include but are not limited to;
- Check constraints
- Functions in SQL Server
- Rules in Postgres
- View, Stored Procedure, Trigger, Rule and Function definitions/code.
We also need to ensure that we correctly maintain certain fixture tables. So we should make it possible to do diffs against particular tables or even against particular views/queries across databases.
We also need the ability to add elements to a white list that we will ignore. i.e. the migrations tables, spatial_ref_sys, geometry_columns etc.