On Thu, Feb 21, 2013 at 12:16 PM, Jeff Janes <jeff.janes@gmail.com> wrote:
> Does the kernel really read a data block from disk into memory in
> order to immediately overwrite it? I would have thought it would
> optimize that away, at least if the writes are sized and aligned to
> 512 or 1024 bytes blocks (which WAL should be).
Now that you mention that I agree it seems strange, but that's what I saw.
/me scratches head
It does seem pretty odd, though.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company