Hi,
I'm considering changing my database schema upgrade routines to recreate
functions and all objects depending on them (e.g. triggers, views) just after
the database server is started. It would make the routines much simpler since
they wouldn't have to depend on the history of the schema.
Does anyone has any experience with recreating all functions and triggers to
upgrade a database schema assuming that during the upgrade there are no client
connections to the database?
Does anyone see any problems with such approach in terms of consistency and
performance? I'm not familiar with PostgreSQL internals and I'm not sure how it
would affect the planner when using various function volatile categories.
The planner pretty much starts from scratch every time a client starts a new database session. You area of concern would be limited to bloating of the pg_* catalogs. Tossing a vacuum in at the end of rebuild should largely solve that problem.
I've done limited work with recreating the entire database, tables included, though obviously only is situations where you can handle filling in table data on every reload. It has its advantages but its quite limited and I'm quickly coming to the conclusion that learning and using a proper database migration tool would be more generally useful. While it probably makes development iteration more difficult if you don't use it in development you aren't testing the tools and code you'd be applying to production.
I'm not sure I have the right answer but having a couple of iterations of doing this with an adhoc and custom framework (using the term loosely) I'm coming to believe this is something that, like backups, you want to find an existing tool and community and join it.
David J.
