Re: [HACKERS] fsync -> fdatasync in backend/storage/file/fd.c - Mailing list pgsql-hackers

The Hermit Hacker wrote:

>         We don't have it (FreeBSD)...what does it do? *raised eyebrow*
> And, how many ppl actually have fsync's enabled?

When you fsync a file it usually costs at least two write operations,
one to write the data and one to update modification/access date, etc.
fdatasync synces only data area of the file without it's
metainformation.

It's not a Linux-only feature. In fact, I'm really not sure if it's
already implemented in Linux (the man page I've got states that in
2.0.23 it was a mere fsync alias) It is a part of POSIX1b standard.

Mike

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