prev/curr/exp and release announcements (Was Re: [ANNOUNCEMENT] Updated: postgresql-8.0.7-1, postgresql-8.1.3-1)

[Igor Peshansky <pechtcha at cs dot nyu dot edu>]

On Sat, 4 Mar 2006, Reini Urban wrote:

> Before you upgrade a postgresql package to a new new major or
> minor version (7.4 => 8.0 => 8.1), be sure to dump all your data before!
> With the new package you will not be able to access your old databases.
> => http://www.postgresql.org/docs/8.0/static/app-pg-dumpall.html
> Minor subrelease updates (e.g. 8.0.4 to 8.0.7) can safely access the
> same database.
>
> Be sure to read the README.cygwin and the postgresql documentation.
>
> I recommend to install the new 8.1 right away, available as [test]
> version from setup, and skip 8.0 altogether. 8.1. has major feature
> improvements over 8.0, esp. when you use tsearch2 and PostGIS
> (crash-recovery on GiST indices, improved concurrency).
>
> I'll keep 8.0 a while as curr, but will drop 7.4 from prev soon.

In light of the above, it seems rather pointless.  I mean, while you have
8.0 as "curr", you might as well keep 7.4 as "prev" (all it wastes is disk
space).  When you move 8.1 into "curr" (and thus 8.0 into "prev"), 7.4 can
be deleted.

Also, what about people who upgrade directly from 7.4 to 8.0/1 after 7.4
has been dropped?  If they didn't read the release announcement (and many
don't), they may end up stuck with unreadable databases, with the usual
solution of "downgrade back, dump the databases, upgrade again"
unavailable to them (well, unless they use Peter's time machine).  Does
postgres incude a dumper tool for prior versions of databases?  Releasing
the dumper tool for 7.4 would make this particular concern go away.

Speaking of making it easy to find/read release announcements, would it be
possible to keep a map from versions to the release announcement message
URLs for the current packages somewhere?  So that setup can use that map
to fire off the appropriate URL?  Once such a map is in place, I think
adding the functionality to use it wouldn't be particularly hard.
	Igor
-- 
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