From emarsden at laas.fr  Wed Mar  3 13:47:46 2004
From: emarsden at laas.fr (Eric Marsden)
Date: Wed, 03 Mar 2004 14:47:46 +0100
Subject: [pg-devel] project created
Message-ID: <wzi7jy259fh.fsf@melbourne.laas.fr>

I have created a web page for the project, visible at

   http://www.common-lisp.net/project/pg/

imported my current pg-dot-lisp sources to the CVS repository, and
tagged them as release 0.20. There aren't many changes relative to
release 0.19.

-- 
Eric Marsden                          <URL:http://www.laas.fr/~emarsden/>



From emarsden at laas.fr  Wed Mar  3 14:13:33 2004
From: emarsden at laas.fr (Eric Marsden)
Date: Wed, 03 Mar 2004 15:13:33 +0100
Subject: [pg-devel] plans for v3 protocol
Message-ID: <wzillmi3to2.fsf@melbourne.laas.fr>

Hi,

pg-dot-lisp currently supports only the v2 frontend/backend protocol,
which is implemented by PostgreSQL versions up to and including 7.3.
Version 7.4 introduces a new v3 protocol, which is more pleasant in
several aspects:

   - better error reporting, with various fields including the type of
     the message, instead of a simple error string. This should allow
     us to improve the mapping onto Common Lisp conditions, by
     introducing more error classes

   - allowing prebound queries with placeholder values (improved
     efficiency for certain use-cases)

   - more regular protocol, so cleaner implementation

The new protocol has been introduced in a backward-compatible manner,
and v7.4 backends are still able to talk the old version of the
protocol, so the current pg-dot-lisp code works fine with PostgreSQL
7.4, though without profiting from these benefits.

Peter Van Eynde has implemented the v3 protocol in Common Lisp. To
integrate this with the current pg-dot-lisp code base, while retaining
compatibility with older PostgreSQL versions, my plan is the
following:

    - create PGCON-V2 and PGCON-V3 classes

    - modify PG-CONNECT to negociate the highest protocol version
      supported by the backend, and return either a PGCON-V2 or
      PGCON-V3 object

    - change PG-EXEC, FN and PG-DISCONNECT to be generic functions
      dispatching on the type of their first argument

    - split out the v2 protocol code from pg.lisp into
      protocol-v2.lisp, and add PVE's code as protocol-v3.lisp

Hopefully this will get us the best of both worlds without too much
pain. I suspect there will be remaining problems with the error
handling, which may have to be separated according to the protocol
version; we'll see. 

[Grr, it seems that posting via the NNTP interface doesn't propagate
 to the mailing list ...]

-- 
Eric Marsden                          <URL:http://www.laas.fr/~emarsden/>



From emarsden at laas.fr  Fri Mar  5 18:14:01 2004
From: emarsden at laas.fr (Eric Marsden)
Date: Fri, 05 Mar 2004 19:14:01 +0100
Subject: [pg-devel] plans for v3 protocol
In-Reply-To: <wzillmi3to2.fsf@melbourne.laas.fr> (Eric Marsden's message of
	"Wed, 03 Mar 2004 15:13:33 +0100")
References: <wzillmi3to2.fsf@melbourne.laas.fr>
Message-ID: <wzismgnxity.fsf@melbourne.laas.fr>

>>>>> "ecm" == Eric Marsden <emarsden at laas.fr> writes:
 
  ecm> - create PGCON-V2 and PGCON-V3 classes
  ecm> 
  ecm> - modify PG-CONNECT to negociate the highest protocol version
  ecm> supported by the backend, and return either a PGCON-V2 or
  ecm> PGCON-V3 object
  ecm> 
  ecm> - change PG-EXEC, FN and PG-DISCONNECT to be generic functions
  ecm> dispatching on the type of their first argument
  ecm> 
  ecm> - split out the v2 protocol code from pg.lisp into
  ecm> protocol-v2.lisp, and add PVE's code as protocol-v3.lisp

I've committed support for this, and it passes the tests against both
PostgreSQL 7.3 and 7.4. There is still some cleanup work to be done.

Next stop: support for prebound queries!
  
-- 
Eric Marsden                          <URL:http://www.laas.fr/~emarsden/>