On 2014-05-08 10:34:04 -0400, Bruce Momjian wrote: > On Thu, May 8, 2014 at 10:16:54AM -0400, Tom Lane wrote: > > > Can we hash just the values, not the keys, in jsonb_ops, and hash the > > > combo in jsonb_hash_ops. That would give us key-only lookups without a > > > recheck. > > > > No, because there's nothing in JSON limiting the length of keys, any more > > than values. > > > > I think the idea of hashing only keys/values that are "too long" is a > > reasonable compromise. I've not finished coding it (because I keep > > getting distracted by other problems in the code :-() but it does not > > look to be very difficult. I'm envisioning the cutoff as being something > > like 128 bytes; in practice that would mean that few if any keys get > > hashed, I think. > > Yes, that would be nice. Ideally we would not be doing this so close to > beta, but it is what it is, and if we need to break binary compatibility > after beta1, at least we have pg_upgrade.
If we break binary compatibility pg_upgrade won't be able to help. Since the data files wont be, err, binary compatibile. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers