[j-pb]

Are you sure that LogicBlox is open-source? I couldn't find anything confirming this.

I'd be very surprised if they were, because they even patented their join algorithm.

[cmrdporcupine]

It's definitely not open source.

Not only is the join algorithm patented, but my understanding is the original authors of it can't even use it, because the LogicBlox IP was acquired but the people moved on.

But some have since gone on to create new stuff @ RelationalAI

[namingisharder]

Nine more years to go. But there has been plenty of quality research on worst case optimal joins in the meantime.