Re: pg_migrator issues

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Alvaro Herrera <alvherre@commandprompt.com>, Bruce Momjian <bruce@momjian.us>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-01-05T16:10:47Z
Lists: pgsql-hackers
Robert Haas <robertmhaas@gmail.com> writes:
> On Tue, Jan 5, 2010 at 11:06 AM, Alvaro Herrera
> <alvherre@commandprompt.com> wrote:
>> Tom Lane wrote:
>>> Good point. Using catversion for the purpose seems a bit ugly but
>>> I have no better ideas.
>> 
>> I thought we had rejected the idea of being able to migrate between
>> alphas. Is migrating between major versions not difficult enough?

> We like a challenge.

The problem with using just major version there is that then we are
*wiring into the on-disk representation* the assumption that pg_migrator
only goes from one major version to the next.  I agree that we're not
likely to start supporting cross-alpha-version migration any time soon,
but I don't think it's wise to foreclose the possibility of ever doing
it.

			regards, tom lane