[_vvhw]

Yes, for almost all databases, although there was a cool paper from the University of Wisconsin Madison a few years ago that showed how to design something that could work without write barriers, and under the assumption that disks don't always fsync correctly:

"the No-Order File System (NoFS), a simple, lightweight file system that employs a novel technique called backpointer based consistency to provide crash consistency without ordering writes as they go to disk"

http://pages.cs.wisc.edu/~vijayc/nofs.htm

[vlovich123]

Does that generalize to databases? My understanding is that file systems are a restricted case of databases that don’t necessarily support all operations (eg transactions are smaller, can’t do arbitrary queries within a transaction, etc etc).

[_vvhw]

I think it would, because if your underlying file system can provide crash consistency then that can be leveraged as a primitive by the database.