Automatic compat checking? (was 7.4 compatibility question)

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