On Tue, Mar 21, 2017 at 1:08 PM, Peter Geoghegan <p...@bowt.ie> wrote: > On Tue, Mar 21, 2017 at 10:04 AM, Robert Haas <robertmh...@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.
Well, I don't want to rule it out either, but if we do a release to which you can't pg_upgrade, it's going to be really painful for a lot of users. Many users can't realistically upgrade using pg_dump, ever. So they'll be stuck on the release before the one that breaks compatibility for a very long time. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers