Re: [HACKERS] gsoc knn spgist
On Fri, Apr 4, 2014 at 11:56 AM, Костя Кузнецов wrote: > I want to implement knn for spgist. I dont have question with knn, but have > questions with implementation of interface. > > i modify pg_am.h (set amcanorderbyop to true in spgist index).Also i modify > pg_amop.h(add > > DATA(insert (4015 600 600 15 o 517 4000 1970 )); > > ) > > explain SELECT * FROM quad_point_tbl ORDER BY p <-> '-2,50' > > Sort (cost=1219.31..1246.82 rows=11003 width=16) >Sort Key: ((p <-> '(-2,50)'::point)) >-> Index Only Scan using sp_quad_ind on quad_point_tbl > (cost=0.15..480.70 r > ows=11003 width=16) > what am I doing wrong? I don't know. I think there are a lot of possibilities based on the information provided. A simple explanation would be that the planner considered the plan you want and found the other one cheaper, but the real cause could well be something else. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
[HACKERS] gsoc knn spgist
Helllo. I want to implement knn for spgist. I dont have question with knn, but have questions with implementation of interface. i modify pg_am.h (set amcanorderbyop to true in spgist index).Also i modify pg_amop.h(add DATA(insert ( 4015 600 600 15 o 517 4000 1970 )); ) explain SELECT * FROM quad_point_tbl ORDER BY p <-> '-2,50' Sort (cost=1219.31..1246.82 rows=11003 width=16) Sort Key: ((p <-> '(-2,50)'::point)) -> Index Only Scan using sp_quad_ind on quad_point_tbl (cost=0.15..480.70 rows=11003 width=16)what am I doing wrong?In a gist index we have : regression=# explain SELECT * FROM point_tbl ORDER BY f1 <-> '-3,0'; QUERY PLAN Index Scan using gpointind on point_tbl (cost=0.13..8.27 rows=7 width=16) Order By: (f1 <-> '(-3,0)'::point) Planning time: 0.166 ms(3 rows) Are there documents about modification access methods? Thanks.Constantine Kuznetsov
Re: [HACKERS] gsoc knn spgist
On Tue, Mar 25, 2014 at 8:16 PM, Костя Кузнецов wrote: > Hello. > > I submit a proposal. But Heikki Linnakangas write comments that i dont > have a plan of implementation. > > My project is knn for spgist. > > Can I ask you a few questions? > > 1. I research a commit gist knn implementation. in gist implementation in > role of queue is ised rtree(with distance comparator) , in spgist > implementation this is List. Can i use rtree in spgist ? if i cant then i > can use. > KNN-GiST uses RB-tree for queue. RB-tree is very different from R-tree. And yes, it can be used in SP-GiST. However, alternative is heap (in-memory structure, not table heap). I don't know why GiST doesn't use heap instead of RB-tree. With best regards, Alexander Korotkov.
[HACKERS] gsoc knn spgist
Hello. I submit a proposal. But Heikki Linnakangas write comments that i dont have a plan of implementation. My project is knn for spgist. Can I ask you a few questions? 1. I research a commit gist knn implementation. in gist implementation in role of queue is ised rtree(with distance comparator) , in spgist implementation this is List. Can i use rtree in spgist ? if i cant then i can use. Thanks. Constantine Kuznetsov
