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Add KNNGIST support to contrib/btree_gist.

This extends GiST's support for nearest-neighbor searches to many of the
standard data types.

Teodor Sigaev
This commit is contained in:
Tom Lane
2011-03-02 14:43:24 -05:00
parent 6094c242d1
commit 8436489c81
40 changed files with 1546 additions and 59 deletions

View File

@ -32,6 +32,14 @@ SELECT count(*) FROM float4tmp WHERE a > -179.0;
302
(1 row)
SELECT a, a <-> '-179.0' FROM float4tmp ORDER BY a <-> '-179.0' LIMIT 3;
a | ?column?
----------+----------
-179 | 0
-189.024 | 10.0239
-158.177 | 20.8226
(3 rows)
CREATE INDEX float4idx ON float4tmp USING gist ( a );
SET enable_seqscan=off;
SELECT count(*) FROM float4tmp WHERE a < -179.0::float4;
@ -64,3 +72,20 @@ SELECT count(*) FROM float4tmp WHERE a > -179.0::float4;
302
(1 row)
EXPLAIN (COSTS OFF)
SELECT a, a <-> '-179.0' FROM float4tmp ORDER BY a <-> '-179.0' LIMIT 3;
QUERY PLAN
-----------------------------------------------
Limit
-> Index Scan using float4idx on float4tmp
Order By: (a <-> (-179)::real)
(3 rows)
SELECT a, a <-> '-179.0' FROM float4tmp ORDER BY a <-> '-179.0' LIMIT 3;
a | ?column?
----------+----------
-179 | 0
-189.024 | 10.0239
-158.177 | 20.8226
(3 rows)