On Thu, May 8, 2014 at 04:37:05PM +0200, Andres Freund wrote: > 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.
Oops, yeah. pg_upgrade only helps with system table changes. We would have to require users to dump/reload any changed tables or recreate any indexs. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers