[uhoh-itsmaciek]

I mostly meant data size on the wire, yeah, but these are all potential issues. In any case, the performance difference between the two approaches is going to heavily depend on your schema and your data, and I suspect the AR works well enough in practice.

And in this example, the data is definitely compressible, but the Postgres wire protocol does not implement compression (it leaves that to tls right now, though CRIME makes that a problem). Adding native compression to the protocol has been on the TODO list for a while: https://wiki.postgresql.org/wiki/Todo#Wire_Protocol_Changes_...