Re: Automatically parsing in-line composite types

Hi,

On 2019-10-29 14:33:00 -0400, Tom Lane wrote:
> Mitar <mmitar(at)gmail(dot)com> writes:
> > I think RowDescription should be extended to provide full recursive
> > metadata about all data types. That would be the best way to do it.
>
> [ shrug... ] In a world where stability of the wire protocol were
> of zero value, maybe we would do that. In the real world, don't
> hold your breath.

Hm. Wouldn't it be fairly easy to allow the client to specify how much
metadata they'd want? I.e. opt-in into getting more complete metadata?

Presumably a lot of clients/applications wouldn't want the server to do
the extra work / use bandwidth for the full details anyway, so making a
more expansive RowDescription be explicitly opt-in would be good, even
if there were zero compatibility concerns.

There's different ways we could do the opt-in. We could use the "_pq_."
startup option stuff to opt in, we could make it an optional parameter
to D messages (it'd be mildly hacky because unfortunately
describe_target is not a counted text), we could use an additional
describe_type etc...

Greetings,

Andres Freund