Hi Carson, Unfortunately, followers are exact replicas of the master database and do not support having changes made to them, so unfortunately your proposed plan won't work.
That said, if the on-disk storage type is compatible, it should be basically instantaneous. Try it on a follower and see if it happens instantly. Otherwise, I recommend you create the new column and migrate the data with a worker process gradually. Gigantic transactions can cause pain for running databases due to a large number of non-visible rows polluting things like indices. Someone else may have more specific advice for your case. Let us know what you discover, -pvh On Tue, Mar 13, 2012 at 9:11 PM, Carson Gross <[email protected]> wrote: > Hi Guys, > > So, we've got ourselves into a bit of a pickle, and have an integer > column in a (100 million plus rows) table that really needs to be > bigint. Not this year, but certainly before we die. I'd like to make > the change sooner rather than later, and I *think* that heroku is > gonna save our bacon here if the following technique could work: > > * Create a database that follows our current db > * In the follower run 'ALTER TABLE my_table ALTER COLUMN id TYPE > bigint' > * Wait a long time > * Wait for the follower to catch up (I assume that given that we are > widening the datatype the follower will work again after the upgrade) > * Move the app over to the new db. > > Does this sound plausible? > > Thanks, > Carson > > -- > You received this message because you are subscribed to the Google Groups > "Heroku" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/heroku?hl=en. > > -- You received this message because you are subscribed to the Google Groups "Heroku" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/heroku?hl=en.
