On Wed, Jan 22, 2014 at 10:08 PM, Jim Nasby <jim@nasby.net> wrote:
>
> Probably more useful is the case of index scans; if we pre-read more data
> from the index we could hand the kernel a list of base relation blocks that
> we know we'll need.
Actually, I've already tried this. The most important part is fetching
heap pages, not index. Tried that too.
Currently, fadvising those pages works *in detriment* of physically
correlated scans. That's a kernel bug I've reported to LKML, and I
could probably come up with a patch. I've just never had time to set
up the testing machinery to test the patch myself.