On 2017-02-02 14:47:53 -0500, Robert Haas wrote:
> I expect that increasing the maximum value of shared_buffers beyond
> what can be stored by an integer could have a noticeable distributed
> performance cost for the entire system. It might be a pretty small
> cost, but then again maybe not; for example, BufferDesc's buf_id
> member would have to get wider, and probably the freeNext member, too.
> Andres already did unspeakable things to make a BufferDesc fit into
> one cache line for performance reasons, so that wouldn't be great
> news.
Yea, we'd have to get rid of BufferDesc's buf_id - but that's not that
hard, just a bit verbose. You can get the buf_id already with a tiny bit
of pointer math. I don't think there should be too many other changes,
but I might be wrong.
Andres
