Re: Named Prepared statement problems and possible solutions

On 08.06.2023 6:18 PM, Dave Cramer wrote:
>
>
> On Thu, 8 Jun 2023 at 11:15, Jan Wieck <jan(at)wi3ck(dot)info> wrote:
>
> On 6/8/23 10:56, Dave Cramer wrote:
> >
> >
> >
> >
> > On Thu, 8 Jun 2023 at 10:31, Jan Wieck <jan(at)wi3ck(dot)info
> > <mailto:jan(at)wi3ck(dot)info>> wrote:
> >
> >     On 6/8/23 09:53, Jan Wieck wrote:
> >      > On 6/8/23 09:21, Dave Cramer wrote:
> >      > The server doesn't know about all the clients of the
> pooler, does
> >     it? It
> >      > has no way of telling if/when a client disconnects from
> the pooler.
> >
> >     Another problem that complicates doing it in the server is
> that the
> >     information require to (re-)prepare a statement in a backend
> that
> >     currently doesn't have it needs to be kept in shared memory.
> This
> >     includes the query string itself. Doing that without shared
> memory in a
> >     pooler that is multi-threaded or based on async-IO is much
> simpler and
> >     allows for easy ballooning.
> >
> >
> > I don't expect the server to re-prepare the statement. If the
> server
> > responds with "statement doesn't exist" the client would send a
> prepare.
>
> Are you proposing a new libpq protocol version?
>
>
> I believe we would need to add this to the protocol, yes.

So it will be responsibility of client to remember text of prepared
query to be able to resend it when statement doesn't exists at server?
IMHO very strange decision. Why not to handle it in connection pooler
(doesn't matter - external or embedded)?