From: Richard Huxton <dev@archonet.com>
To: Neil Conway <neilc@samurai.com>,
	Bruce Momjian <pgman@candle.pha.pa.us>
Subject: Automatic compat checking? (was 7.4 compatibility question)
Date: Wed, 22 Oct 2003 10:30:52 +0100
User-Agent: KMail/1.5
Cc: Christopher Kings-Lynne <chriskl@familyhealth.com.au>,
	Tom Lane <tgl@sss.pgh.pa.us>,
	PostgreSQL Hackers <pgsql-hackers@postgresql.org>
References: <200310220508.h9M584f23271@candle.pha.pa.us>
	<1066804676.371.92.camel@tokyo>
In-Reply-To: <1066804676.371.92.camel@tokyo>
MIME-Version: 1.0
Content-Type: text/plain;
  charset="utf-8"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Message-Id: <200310221030.52736.dev@archonet.com>

On Wednesday 22 October 2003 07:37, Neil Conway wrote:
> The second audience is the people who are really interested in exactly
> what has changed between the new release of PostgreSQL and the previous
> release series. It is important that we make it easy for an admin
> planning a PostgreSQL upgrade at a fairly large site to be able to see
> what changes in PostgreSQL have been made, and what changes will be
> necessary in their own applications. 

Something I was pondering the other day was whether a pg_compat_chk utility 
would be practical/desirable. You run it against your existing database / 
schema dump and it prints a set of warnings:

Old version = 7.2.1
New version = 7.4.0

Warning: schema support introduced (v7.3)
  all objects will be placed in the default schema
Failure: DEFAULT 'now' not supported (v7.4)
  table1.column2
  table2.column3
Notice: timestamp now holds milliseconds by default (v7.3)
  tableX.whatever

My main concern would be that a 90% solution might be worse than nothing at 
all.
Incidentally, this is not idle speculation, but something I might well have 
time to stick in gborg during the 7.5 devt cycle.

-- 
  Richard Huxton
  Archonet Ltd