On Tue, Mar 21, 2017 at 10:04 AM, Robert Haas <robertmhaas@gmail.com> wrote:
> I think that's a good question. I previously expressed similar
> concerns. On the one hand, it's hard to ignore the fact that, in the
> cases where this wins, it already buys us a lot of performance
> improvement. On the other hand, as you say (and as I said), it eats
> up a lot of bits, and that limits what we can do in the future. On
> the one hand, there is a saying that a bird in the hand is worth two
> in the bush. On the other hand, there is also a saying that one
> should not paint oneself into the corner.
Are we really saying that there can be no incompatible change to the
on-disk representation for the rest of eternity? I can see why that's
something to avoid indefinitely, but I wouldn't like to rule it out.
--
Peter Geoghegan