__checkpoint_db_internal is a long and complex function, it currently has an extremely high complexity score of 52, with over 250 LOC. The accepted limit for complexity score is 20. The code complexity of a function is measured via cyclomatic complexity (the number of separate paths that can be taken in a function). Breaking down the function into separate parts will reduce the code complexity and improve maintainability. By refactoring the function, one of the side effects would be to get to a lower complexity score.

This work should not change the checkpoint behaviour.