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Cube extension kNN support

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Introduce distance operators over cubes:
<#> taxicab distance
<->  euclidean distance
<=> chebyshev distance

Also add kNN support of those distances in GiST opclass.

Author: Stas Kelvich
This commit is contained in:
Teodor Sigaev
2015-12-18 14:38:27 +03:00
parent 3d0c50ffa0
commit 33bd250f6c
12 changed files with 1684 additions and 4 deletions
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53
contrib/cube/sql/cube.sql
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@ -325,6 +325,41 @@ SELECT cube_inter('(1,2,3)'::cube, '(5,6,3)'::cube); -- point args
SELECT cube_size('(4,8),(15,16)'::cube);
SELECT cube_size('(42,137)'::cube);
-- Test of distances
--
SELECT cube_distance('(1,1)'::cube, '(4,5)'::cube);
SELECT '(1,1)'::cube <-> '(4,5)'::cube as d_e;
SELECT distance_chebyshev('(1,1)'::cube, '(4,5)'::cube);
SELECT '(1,1)'::cube <=> '(4,5)'::cube as d_c;
SELECT distance_taxicab('(1,1)'::cube, '(4,5)'::cube);
SELECT '(1,1)'::cube <#> '(4,5)'::cube as d_t;
-- zero for overlapping
SELECT cube_distance('(2,2),(10,10)'::cube, '(0,0),(5,5)'::cube);
SELECT distance_chebyshev('(2,2),(10,10)'::cube, '(0,0),(5,5)'::cube);
SELECT distance_taxicab('(2,2),(10,10)'::cube, '(0,0),(5,5)'::cube);
-- coordinate access
SELECT cube(array[10,20,30], array[40,50,60])->1;
SELECT cube(array[40,50,60], array[10,20,30])->1;
SELECT cube(array[10,20,30], array[40,50,60])->6;
SELECT cube(array[10,20,30], array[40,50,60])->0;
SELECT cube(array[10,20,30], array[40,50,60])->7;
SELECT cube(array[10,20,30], array[40,50,60])->-1;
SELECT cube(array[10,20,30], array[40,50,60])->-6;
SELECT cube(array[10,20,30])->3;
SELECT cube(array[10,20,30])->6;
SELECT cube(array[10,20,30])->-6;
-- "normalized" coordinate access
SELECT cube(array[10,20,30], array[40,50,60])~>1;
SELECT cube(array[40,50,60], array[10,20,30])~>1;
SELECT cube(array[10,20,30], array[40,50,60])~>2;
SELECT cube(array[40,50,60], array[10,20,30])~>2;
SELECT cube(array[10,20,30], array[40,50,60])~>3;
SELECT cube(array[40,50,60], array[10,20,30])~>3;
SELECT cube(array[40,50,60], array[10,20,30])~>0;
SELECT cube(array[40,50,60], array[10,20,30])~>4;
SELECT cube(array[40,50,60], array[10,20,30])~>(-1);
-- Load some example data and build the index
--
CREATE TABLE test_cube (c cube);
@ -336,3 +371,21 @@ SELECT * FROM test_cube WHERE c && '(3000,1000),(0,0)' ORDER BY c;
-- Test sorting
SELECT * FROM test_cube WHERE c && '(3000,1000),(0,0)' GROUP BY c ORDER BY c;
-- kNN with index
SELECT *, c <-> '(100, 100),(500, 500)'::cube as dist FROM test_cube ORDER BY c <-> '(100, 100),(500, 500)'::cube LIMIT 5;
SELECT *, c <=> '(100, 100),(500, 500)'::cube as dist FROM test_cube ORDER BY c <=> '(100, 100),(500, 500)'::cube LIMIT 5;
SELECT *, c <#> '(100, 100),(500, 500)'::cube as dist FROM test_cube ORDER BY c <#> '(100, 100),(500, 500)'::cube LIMIT 5;
-- kNN-based sorting
SELECT * FROM test_cube ORDER BY c~>1 LIMIT 15; -- ascending by 1st coordinate of lower left corner
SELECT * FROM test_cube ORDER BY c~>4 LIMIT 15; -- ascending by 2nd coordinate or upper right corner
SELECT * FROM test_cube ORDER BY c~>1 DESC LIMIT 15; -- descending by 1st coordinate of lower left corner
SELECT * FROM test_cube ORDER BY c~>4 DESC LIMIT 15; -- descending by 2nd coordinate or upper right corner
-- same thing for index with points
CREATE TABLE test_point(c cube);
INSERT INTO test_point(SELECT cube(array[c->1,c->2,c->3,c->4]) FROM test_cube);
CREATE INDEX ON test_point USING gist(c);
SELECT * FROM test_point ORDER BY c~>1, c~>2 LIMIT 15; -- ascending by 1st then by 2nd coordinate
SELECT * FROM test_point ORDER BY c~>4 DESC LIMIT 15; -- descending by 1st coordinate