It's not so much as how different it is from an architectural standpoint as it is about the sheer magnitude of such a feature. All open-source communities have processes which help maintain high quality, but also add a bit of red tape. I don't think we'd be able to operate at the pace we want if we were pushing every change upstream.

However, we love Postgres and plan on actively merging upstream releases!

Cofounder at Couchbase here.

Is the license decision driven by business or is there some dependency that pushes you to GPL? For us Apache 2.0 has been worth it even when other companies use our code in their products.

And not just the GPL, but the AGPL. That one caught me by surprise. Does this mean there is going to be a MySQL-style dual-licensing situation in the future? (or is this already the case?)

PipelineDB is actually licensed under the GPLv3. We accidentally updated our files with the AGPL earlier today by mistake but have since rectified that. Apologies for the mixup!

As much as thank you comments are downvoted here I'll still say: Thank you! Same goes to everyone else who avoids hasseling developers everywhere with AGPL.