Обсуждение: "An old version of the database format was found."

A very minor rant.

I usually run 7.4.1 at home, but today I need to do some testing on 
7.2.1 so I downgraded my RPM installation. When trying to start 
postgresql with /etc/init.d/postgresql, it fails with this message:

"An old version of the database format was found.\nYou need to upgrade 
the data format before using PostgreSQL.\nSee (Your System's 
documentation directory)/postgresql-7.4/README.rpm-dist for more 
information."

When in fact the database format was newer. Also I tried 7.4.1 with a 
data directory where PG_VERSION is changed to 7.5 by purpose. Same message.

Wouldn't it be a bit more helpful if the error message is along the line 
of "Database format is different (... was expecting version X.Y but 
found P.Q instead...)"

-- 
dave

David Garamond <lists@zara.6.isreserved.com> writes:
> A very minor rant.
> I usually run 7.4.1 at home, but today I need to do some testing on 
> 7.2.1 so I downgraded my RPM installation. When trying to start 
> postgresql with /etc/init.d/postgresql, it fails with this message:

> "An old version of the database format was found.\nYou need to upgrade 
> the data format before using PostgreSQL.\nSee (Your System's 
> documentation directory)/postgresql-7.4/README.rpm-dist for more 
> information."

Can't help you on what 7.2 says about this, unless you'd like to buy me
a time machine.

> When in fact the database format was newer. Also I tried 7.4.1 with a 
> data directory where PG_VERSION is changed to 7.5 by purpose. Same message.

Oh?  I did the same and got

FATAL:  database files are incompatible with server
DETAIL:  The data directory was initialized by PostgreSQL version 7.5,
which is not compatible with this version 7.4.3.

I'm quite sure this message didn't change between 7.4.1 and 7.4.3...
        regards, tom lane