On 13 May 2004, at 3:34 pm, Dan Nelson wrote:
>>> Pros: performance and bypassing the filesystem cache.
> I believe most OSes support direct file access which either bypasses or
> minimizes cache effects, and InnoDB will enable it if possible.
> Solaris direct file I/O performance on UFS is within a couple percent
> of raw partitions, for example.
This is all very well, but on some systems, surely the OS filesystem
cache is a bonus, not a hindrance. Take for example a four-way X86
system with 16 GB RAM. I've seen people talk about such machines on
MySQL can't use all that memory itself, so it makes sense to allow the
OS to cache as much disk space as possible in the memory that MySQL
can't use directly?