Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Mon, Oct 24, 2011 at 3:35 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> I wonder how trustworthy the measure of the visibilitymap_test call site
>> as a consumer of cycles really is.
> I'm not sure either. I guess we could try short-circuiting
> visibilitymap_test and see what that does to performance (let's leave
> correct answers out of it).
That would conflate the cost of the call with the cost of the function.
Maybe you could try manually inlining the visibility test?
regards, tom lane