Do you really need to allow web server connections to the database during a schema migration ? Why not locking them up either with pg_hba.cong or a firewal rule or symply shut it off temporarily ?
Cheers, A.A.
On Fri, Mar 21, 2014 at 10:46 AM, Ken Barber <ken@bob.sh> wrote:
Hi there,
I was just wondering if anyone has some general advice for how to ensure a schema migration for an application has exclusivity during its run.
This is to avoid silly things like, if someone leaves an application server running during migration the migration should be able to lock somehow to avoid any changes while it is running.
I've taken a look at LOCK TABLE, which can lock a table obviously (and I can obviously lock _all_ tables to fake a LOCK DATABASE), but I'm wondering if someone has some opinion around just raising the transaction isolation level to achieve similar goals?
Any lessons learnt and best practices would be much appreciated :-). ken.
