@chitralverma thanks for the discussion. We've been referred to sqlglot a few times to convert from/to our dialect (we invite contributions!).

That said, I doubt sqlglot is a substitute for Apache Calcite in any serious capacity; syntactically translating between dialects is not the same as a full-featured SQL frontend, optimizer and compiler infrastructure. Datafusion would be a better comparison point, but at the time we started this project, it was pretty nascent.

Do you know of projects that managed to do such a replacement?

Having a tool to port programs to Feldera SQL would be very useful.
Performing semantics-preserving transformations between SQL dialects sounds like a huge effort. I think in general it's impossible - each SQL dialect has some unique features which may be impossible to model exactly in other dialects.

Calcite is not even a dialect, it has a large number of configuration knobs that can make it look like other dialects to some degree, but it doesn't really match any one exactly. We don't use its default settings, and some of the functions which we consider "wrong" we reimplement in a different way, when we can.

But perhaps people would be happy with just a coarse transformation, which they can tweak by hand. But for this purpose some of our customers have used LLMs quite successfully.