Re: Fwd: Apple Darwin disabled fsync? - Mailing list pgsql-hackers

From Greg Stark
Subject Re: Fwd: Apple Darwin disabled fsync?
Date
Msg-id 87zmxzuo0m.fsf@stark.xeocode.com
Whole thread Raw
In response to Fwd: Apple Darwin disabled fsync?  (Peter Bierman <bierman@apple.com>)
List pgsql-hackers
Peter Bierman <bierman@apple.com> writes:

> > In most cases you do not need such a heavy handed operation and fsync() is
> > good enough.

Really? Can you think of a single application for which this definition of
fsync is useful?

Kernel buffers are transparent to the application, just as the disk buffer is.
It doesn't matter to an application whether the data is sitting in a kernel
buffer, or a buffer in the disk, it's equivalent. If fsync doesn't guarantee
the writes actually end up on non-volatile disk then as far as the application
is concerned it's just an expensive noop.

-- 
greg



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