Teodor Sigaev <[EMAIL PROTECTED]> writes: >> operations such as page splits. Do we need to change the planner to >> assume that this only works nicely for btree?
> It seems to that direction (backward or forward) has meaning only for > indexes with amcanorder = true. With amcanorder=false results will be > occasionally for any direction. Well, no; amcanorder specifies that the index can return results that are sorted according to some externally meaningful ordering. The question at hand is just whether the results of a single indexscan are self-consistent. That's a property that can reasonably be expected to hold regardless of amcanorder; it does hold for hash indexes for instance. (In the case of hash we have to forbid splitting a bucket that's actively being scanned in order to make it true.) regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers