Data Migrations in Production


#1

General question - when you deploy a new production version, how do
you normally handle the data migration? I’m leery of applying “spot”
changes directly to the prod DB - I would prefer to have an unchanged
version to roll back to. (Could always backup and restore of
course…) I haven’t seen much literature on running a data
migration script to move from one prod DB to another with changes
applied on the fly, so I’m guessing people don’t do that…


#2

On 27 Dec 2008, at 03:04, Mike wrote:

General question - when you deploy a new production version, how do
you normally handle the data migration? I’m leery of applying “spot”
changes directly to the prod DB - I would prefer to have an unchanged
version to roll back to. (Could always backup and restore of
course…) I haven’t seen much literature on running a data
migration script to move from one prod DB to another with changes
applied on the fly, so I’m guessing people don’t do that…

As far as being able to roll back to stuff, we just stop replication
between the master and the primary slave while we do migrations etc…
If it all goes tits up we can fallback to the slave which has the
database prior to the migrations and also has the previous version of
any code that it runs.

Fred