Michael Nolan <htfoot@xxxxxxxxx> writes: > It also appears you cannot group on a column of type xid. You can in 8.4 and up. Previous versions only know how to GROUP BY sortable columns, which requires a btree opclass, which xid doesn't have and really can't have because it doesn't have a linear ordering. There is a hash opclass for it, though, so in versions that know how to GROUP BY using hashing, it'll work. > Would adding a <> operator enable that? No, it's pretty irrelevant ... regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
