On Fri, Aug 30, 2019 at 2:44 PM Andrey Borodin <x4...@yandex-team.ru> wrote: > > 30 авг. 2019 г., в 3:47, Alexander Korotkov <a.korot...@postgrespro.ru> > написал(а): > > 1) Binary search in non-leaf pages instead of probing each key is much faster. > > > That's a neat idea, but key union breaks ordering, even for z-order. > for two sets of tuples X and Y > if for any i,o from N, Xi < Yo > does not guaranty union(X) < union (Y) > > For example consider this z-ordered keyspace (picture attached) > > union(5, 9) is z-order-smaller than union(4,4) > > I'm not even sure we can use sorted search for choosing subtree for insertion.
Sorry, I didn't explain my proposal in enough details. I didn't mean B-tree separator keys would be the same as union key (MBR). I mean B-tree on Z-values, which maintains union key in addition to separator keys. So, you select downlink to insert using separator Z-values and then also extend union key (if needed). It's probably still not enough detail yet. I'll try to spend more time for more detailed description later. > > How do you think, should I supply GiST-build patch with docs and tests and > add it to CF? Or do we need more design discussion before? +1 for adding to CF. ------ Alexander Korotkov Postgres Professional: http://www.postgrespro.com The Russian Postgres Company
