On 2015-08-19 10:55:00 -0400, Tom Lane wrote:
> My own thought about reducing the cost of XidInMVCCSnapshot, if that
> proves necessary, is that maybe it would be worth the trouble to sort
> the arrays so we could use binary search. That would increase the
> cost of snapshot acquisition noticeably though.
It's also considerably more expensive for search in many cases because
it's very hard to predict (branching and prefetching). I doubt it'd be
worthwhile.