On Mon, 2012-04-16 at 21:16 +0200, Guillaume Lelarge wrote: > On Mon, 2012-04-16 at 16:46 +0100, Roger Leigh wrote: > > On Mon, Apr 16, 2012 at 10:22:19AM -0500, Merlin Moncure wrote: > > > On Mon, Apr 16, 2012 at 10:05 AM, Roger Leigh <rleigh@xxxxxxxxxxxxx> wrote: > > > > The reason for the above is that I'd very much like to be able to > > > > version my entire application's schema using the extension mechanism > > > > (or something based upon the ideas in the extensions mechanism). Since > > > > SCHEMA is already taken, maybe CREATE/ALTER/DROP_APPLICATION. This > > > > would permit easy installation and upgrade of all the objects relating > > > > to a single application installed in the database. > > > > > > not following that -- it sounds like you are trying to hook into the > > > grammar? that's something you can't do through an extension. but it's > > > an interesting thought to do application versioning through the > > > extension system...i'm pretty sure it hasn't been tried. there may be > > > some pitfalls though. > > > > This was mainly just speculative--in the case that the extension > > system didn't support everything I wanted, I was wondering if > > extending the grammar would be a viable approach; obviously it would > > require other work too! > > > > Every project I've worked on which uses PostgreSQL has independently > > implemented its own set of installation and upgrade scripts, which > > has typically included some form of table for storing the current > > schema version and other settings to allow the scripts to safely do > > their job. However, I'm not a big fan of unnecessary wheel > > reinvention, and if PostgreSQL could provide a standard mechanism > > for doing this which all applications could utilise, that would be > > (IMO) an absolutely fantastic feature. If extensions can be used > > as they stand to realise this, then that's absolutely great: the > > end user installation instructions can be reduced to > > CREATE EXTENSION myapplication; > > and the equivalent for upgrades. I'm not sure if another keyword > > would be useful in this context, since this is much more than a > > single extension, it's an entire schema. > > > > Won't work if you care to save your database with pg_dump. Any tables > created by extensions won't be saved with pg_dump. All you will get is a > "CREATE EXTENSION myapplication;", and no data. > Actually, I'm not completely right here. You may configure your extension to allow your tables to be dumped. See http://www.postgresql.org/docs/9.1/interactive/extend-extensions.html#AEN51978 for details. IOW, it may work, but you need to be extra-careful. I don't know anyone doing this right now. -- Guillaume http://blog.guillaume.lelarge.info http://www.dalibo.com -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
