Re: DRDA, network protocol, and documentation

On 5 Feb 2002, Hannu Krosing wrote:

> On Tue, 2002-02-05 at 15:39, Brian Bruns wrote:
> > Hi all,
> >
> > I'm working on an implementation of the DRDA protocol and am planning on
> > modifying postgresql to support DRDA. (DRDA is an Open Group standard
> > protoc
>
> Hopefully this will bring us PREPARE/EXECUTE support too.
>
> BTW, does DRDA have a notion of LISTEN/NOTIFY ?

Not that I'm aware of, although the spec is really big so there are some
pieces I haven't fully groked. There is ongoing standards activities for
DRDA, but it's closed to TOG members apparently, but from what I can tell
they are adding lots of object features, IPv6 stuff, unicode, etc...

> Protocol is quite simple and AFAIK fully documented in Developers Guide.

I ran it through ethereal, and got a pretty good flavor for it.

>
> The networking code seems to be "Traffic Cop" directory in
> src/backend/tcop/postgresql.c

Actually some is in libpq, some is in tcop, some in executor. Seems to be
a bit of a mess if you don't mind me saying so. ;-)

What I would propose is a net/ directory that has interface that is called
by all the other code, and net layer would call the appropriate protocol
stuff. So, all the protocol stuff will be in exactly one place.

> > I also noticed on the TODO list someone has put SQL*Net support as a
> > network protocol. Is this a serious plan or just a pipedream? Part of
> > what I'm aiming to do is make the network protocol stuff fairly modular so
> > you could support the current protocol, and DRDA, and presumably SQL*Net
> > or TDS (Microsoft/Sybases protocol), etc...
>
> XML-over-HTTP/1.1 would also be really cool, even more so if server
> could apply XSLT transforms to results on the fly :)

This could be supported as just another protocol ;-)

Brian