alt Hacker Newsif there is a hole in the log then the end of the log is before the hole. you do have to have checksums on log chunks, and better a kind of rolling hash, but you're really just talking about he number of entires that we would have liked to commit but didn't
Yeah this is a good point, and maybe a hole wasn't the right way to explain myself. The point is that the way a WAL is supposed to work is that the main data store always lags behind the WAL, so that if a partial operation (always idempotent) occurs on shutdown it is replayed on start up and fixed. In the case I describe, because of a lack of fsync it's possible for the WAL to lag the main data store, so partial operations will not be fixed on start up.