On Wed, 2023-03-22 at 14:42 -0400, Tom Lane wrote: > This isn't going to help much unless we change the wire protocol > so that RowDescription messages carry these UUIDs instead of > (or in addition to?) the OIDs of the column datatypes. While > that's not completely out of the question, it's a heavy lift > that will affect multiple layers of client code along with the > server.
I'm not sure that's a hard requirement. I pointed out a similar solution for type names here:
In other words: if the Bind message depends on knowing the OID mappings, that forces an extra round-trip; but if the client doesn't need the mapping until it receives its first result, then it can use pipelining to avoid the extra round-trip.
This overcomplicates things for the JDBC driver. We don't pipeline queries, well we do for batch queries but those are special.
(I haven't actually tried it and I don't know if it's very reasonable to expect the client to do this.)
> Also, what about container types? I doubt it's sane for > array-of-foo to have a UUID that's unrelated to the one for foo. > Composites and ranges would need some intelligence too if we > don't want them to be unduly complicated to process.
That's a good point. I don't know if that is a major design issue or not; but it certainly adds complexity to the proposal and/or clients implementing it.
