Re: Clock sweep not caching enough B-Tree leaf pages?

Stephen Frost <sfrost@snowman.net> writes:
> I wonder if it would help to actually tell the OS to read in buffers
> that we're *evicting*...  On the general notion that if the OS already
> has them buffered then it's almost a no-op, and if it doesn't and it's
> actually a 'hot' buffer that we're gonna need again shortly, the OS will
> have it.

But if it's actually gone cold, you're just forcing unnecessary read I/O,
not to mention possibly causing something slightly warmer to be lost from
kernel cache.
        regards, tom lane