Re: [HACKERS] Performance while loading data and indexing

Neil Conway wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > The paper does recommend ext3, but the differences between file systems
> > are very small.
> 
> Well, I only did a very rough benchmark (a few runs of pgbench), but
> the results I found were drastically different: ext2 was significantly
> faster (~50%) than ext3-writeback, which was in turn significantly
> faster (~25%) than ext3-ordered.

Wow.  That leaves no good Linux file system alternatives.  PostgreSQL
just wants an ordinary file system that has reliable recovery from a
crash.

> > Also, though ext3 is slower, turning fsync off should make ext3 function
> > similar to ext2.
> 
> Why would that be?

I assumed it was the double fsync for the normal and journal that made
the journalling file systems slog.

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