Allow SUBSCRIBE ... UP TO over http

[RobinClowers]

Feature request

Currently, no subscribe queries are allowed over the http interface. It would be useful if you could run a bounded subscribe (SUBSCRIBE ... UP TO) over http.

[maddyblue]

#28000 (comment) for why this is not a simple PR that just enables this feature.

[maddyblue]

As another possibility: if we added a CONSOLIDATE keyword to SUBSCRIBE that produced (row, diff) pairs (no timestamp, it is assumed to be the UP TO timestamp) would that solve your problem? We could make that return a normal rows object. Or do you need the fine grained timestamped updates?

[RobinClowers]

For the specific use case I had in mind, just the values would be fine. That said, I don't know if it's worth adding another option that changes the format just for this case? I can imagine other cases where I wanted to graph or show a table of previous hydration times (or other introspection data that changes slowly), and I would have to fall back to a websocket connection for those cases.