On Mon, 28 Nov 2005, David Boreham wrote:
> Gavin Sherry wrote:
>
> > MySQL, Oracle and others implement read-ahead threads to simulate async IO
>
> I always believed that Oracle used async file I/O. Not that I've seen their
> code, but I'm fairly sure they funded the addition of kernel aio to Linux
> a few years back.
That's right.
>
> But....Oracle comes from a time long ago when threads and decent
> filesystems didn't exist, so some of the things they do may not be
> appropriate
> to add to a product that doesn't have them today.
The paper I linked to seemed to suggest that they weren't using async IO
in 9.2 -- which is fairly old. I'm not sure why the authors didn't test
10g.
Gavin
