On Thu, Jun 30, 2016 at 09:16:49AM -0500, Merlin Moncure wrote:
> It's not really necessary to create version down scripts. In five
> years of managing complex database environments we've never had to
> roll a version back and likely never will; in the event of a disaster
> it's probably better to restore from backup anyways.
Also, a very robust approach to rollback is to clone the
existing databse before upgrading the schema (if feasible due
to size). This is the approach GNUmed uses - migration
scripts are up only, as many of them as possible are
idempotent, and we clone the existing database into a new one
before the upgrade is run. That way, users can go back to the
previous database immediately anytime and reattempt the
upgrade when convenient.
Karsten
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