[zapov]

But I find it highly valuable to have a single model representation as a source of truth. You can see how it works in practice here: https://github.com/ngs-doo/revenj

Also, there are no tools for describing DB schemas that way (except if you consider DB DDL such a schema). So my DSL is used as uniform data format. And it's not a problem of mapping between formats, but within the logic required to do such a mapping. It can't be expressed as a simple transformation, compiler is required to analyze and transform it appropriately in various scenarios. And if you want optimizations, good luck with "simple mapping".

So yeah, it's complicated, but it needs to be complicated to support simple modeling DSL. Otherwise you are better off with having several DB schemas, various POOs, Protobuf/Flatbuffer IDL etc...

[sklogic]

In this case you need four DSLs - your core model and three DSLs for mapping the model to the specific storage backends.