[petereisentraut]

> Care to explain why you think NULLS DISTINCT is the "right" default behavior? What problems does it solve to warrant additional complexity by default?

It's the most consistent with the equality behavior of null values elsewhere.

[jeff-davis]

I generally agree that, in most cases, you want the NULLS DISTINCT behavior. But thank you for providing such a developer-friendly feature that allows flexibility here!

NULL in SQL is not terribly consistent overall. Sometimes NULL is treated like "unknown" and sometimes more like "n/a". And the interaction with non-scalar types (like records) is pretty strange. Also, it's common for ORMs to map the app language's NULL (or None/Nil/whatever) to SQL NULL, which adds its own nuance. So I can see this being a useful feature.