On Wed, Apr 4, 2018 at 10:40:16AM +0800, Craig Ringer wrote:
> The trouble with direct I/O is that it pushes a _lot_ of work back on
> PostgreSQL regarding knowledge of the storage subsystem, I/O scheduling, etc.
> It's absurd to have the kernel do this, unless you want it reliable, in which
> case you bypass it and drive the hardware directly.
>
> We'd need pools of writer threads to deal with all the blocking I/O. It'd be
> such a nightmare. Hey, why bother having a kernel at all, except for drivers?
I believe this is how Oracle views the kernel, so there is precedent for
this approach, though I am not advocating it.
--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com
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