[fdr]

yeah, that one is a path dependency issue, re: postgres. I'm not sure if it's well reasoned past inertia after the initial "it's new, let's not throw the entire user base into it at once", but at the very least, it will complicate pg_upgrade somewhat. WiredTiger didn't really have that path dependency, being itself new to Mongo to shore up the storage situation.

It's probably about time to swap the default, but some people's once-working pg_upgrade programs that they haven't looked at in a while might break. Probably okay; those things need to happen...once in a while. I suppose some people that resent the overhead of Postgres checksumming atop their ZFS/btrfs/dm-integrity/whatever stacks, but they are somewhat rarer.

[funny_falcon]

Most weird thing: PostgreSQL's checksum algorithm is almost free on modern processors. It uses SIMD instructions extremely well in optimized builds. I've never seen him in CPU profile despite I always enable it.

There are no any reasons to not enable it (except pg_upgrade).