> -----Original Message-----
> From: Bruce Momjian [mailto:pgman@candle.pha.pa.us]
>
> > Peter Eisentraut wrote:
> >
> > > On Tue, 2 May 2000, Hiroshi Inoue wrote:
> > >
> > > > What kind of backward compatibity is required for psql etc..?
> > >
> > > The knowledge about the system catalogs is already pretty
> deep so keeping
> > > track of changes across versions is similar to the initdb problem:
> >
> > Yes there's another example. PostgreSQL odbc driver wasn't able to talk
> > to 7.0 backend until recently due to the change int28 -> int2vector.
> > Now odbc driver could talk to all the backends from 6.2.
> > We may have to hold some reference table between system catalogs
> > and client appl/lib.
>
> The big reason for the change is that int2vector is now more than 8
> int2's (now 16), so there may be internal changes as well as a name
> change for applications.
>
Yes I know the reason. It's only a example that changes of system
catalogs affects not only a backend application but also client libraries.
Unfortunately I don't know the dependency between backend and
clients well. In addtion current release style of PostgreSQL that
releases both server and clients all together seems to let people
forget the independecy of clients.
In general client libraries/applications have to keep backward
compatibility as possible,so it isn't enough for clients to be able to
talk to the latest version of PostgreSQL servers.
Comments ?
Regards.
Hiroshi Inoue
Inoue@tpf.co.jp