On 11/27/18, 2:46 PM, "Andres Freund" <and...@anarazel.de> wrote: > On 2018-11-27 20:43:06 +0000, Bossart, Nathan wrote: >> I don't have exact figures to share, but yes, a huge number of calls >> to sync_file_range() and fsync() can use up a lot of time. Presumably >> Postgres processes files individually instead of using sync() because >> sync() may return before writing is done. Also, sync() would affect >> non-Postgres files. However, it looks like Linux actually does wait >> for writing to complete before returning from sync() [0]. > > sync() has absolutely no way to report errors. So, we're never going to > be able to use it. Besides, even postgres' temp files would be a good > reason to not use it.
Ah, I see. Thanks for clarifying. Nathan
