[bmdavi3]

This is cool.

Another alternative would be to use postgres savepoints, which are like transactions inside transactions, as a wrapper around each migration. You can do the same thing - set lock_timeout and catch errors when those values are exceeded, and try the transaction again.

Provide an option to run the handful of operations that can't be run inside a transaction as an escape hatch, and then you can retain the ability to run migrations inside transactions, which is usually a good thing.

[tbicr]

Unfortunately savepoints live only in transaction and ACCESS EXCLUSIVE will be released only on whole transaction commit/rollback, so look like no benefits with savepoints for schema migrations to compare with plain transaction.