mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-08-31 02:07:21 +02:00
9f984ba6d2
Commit 16fa9b2b30 introduced a faster way to build GiST indexes, by
sorting all the data. This commit adds the sortsupport functions needed
to make use of that feature for btree_gist.
Author: Andrey Borodin
Discussion: https://www.postgresql.org/message-id/2F3F7265-0D22-44DB-AD71-8554C743D943@yandex-team.ru
99 lines
2.0 KiB
Plaintext
99 lines
2.0 KiB
Plaintext
-- float4 check
|
|
CREATE TABLE float4tmp (a float4);
|
|
\copy float4tmp from 'data/float4.data'
|
|
SET enable_seqscan=on;
|
|
SELECT count(*) FROM float4tmp WHERE a < -179.0;
|
|
count
|
|
-------
|
|
244
|
|
(1 row)
|
|
|
|
SELECT count(*) FROM float4tmp WHERE a <= -179.0;
|
|
count
|
|
-------
|
|
245
|
|
(1 row)
|
|
|
|
SELECT count(*) FROM float4tmp WHERE a = -179.0;
|
|
count
|
|
-------
|
|
1
|
|
(1 row)
|
|
|
|
SELECT count(*) FROM float4tmp WHERE a >= -179.0;
|
|
count
|
|
-------
|
|
303
|
|
(1 row)
|
|
|
|
SELECT count(*) FROM float4tmp WHERE a > -179.0;
|
|
count
|
|
-------
|
|
302
|
|
(1 row)
|
|
|
|
SELECT a, a <-> '-179.0' FROM float4tmp ORDER BY a <-> '-179.0' LIMIT 3;
|
|
a | ?column?
|
|
------------+-----------
|
|
-179 | 0
|
|
-189.02386 | 10.023865
|
|
-158.17741 | 20.822586
|
|
(3 rows)
|
|
|
|
SET client_min_messages = DEBUG1;
|
|
CREATE INDEX float4idx ON float4tmp USING gist ( a );
|
|
DEBUG: building index "float4idx" on table "float4tmp" serially
|
|
DEBUG: using sorted GiST build
|
|
CREATE INDEX float4idx_b ON float4tmp USING gist ( a ) WITH (buffering=on);
|
|
DEBUG: building index "float4idx_b" on table "float4tmp" serially
|
|
DROP INDEX float4idx_b;
|
|
RESET client_min_messages;
|
|
SET enable_seqscan=off;
|
|
SELECT count(*) FROM float4tmp WHERE a < -179.0::float4;
|
|
count
|
|
-------
|
|
244
|
|
(1 row)
|
|
|
|
SELECT count(*) FROM float4tmp WHERE a <= -179.0::float4;
|
|
count
|
|
-------
|
|
245
|
|
(1 row)
|
|
|
|
SELECT count(*) FROM float4tmp WHERE a = -179.0::float4;
|
|
count
|
|
-------
|
|
1
|
|
(1 row)
|
|
|
|
SELECT count(*) FROM float4tmp WHERE a >= -179.0::float4;
|
|
count
|
|
-------
|
|
303
|
|
(1 row)
|
|
|
|
SELECT count(*) FROM float4tmp WHERE a > -179.0::float4;
|
|
count
|
|
-------
|
|
302
|
|
(1 row)
|
|
|
|
EXPLAIN (COSTS OFF)
|
|
SELECT a, a <-> '-179.0' FROM float4tmp ORDER BY a <-> '-179.0' LIMIT 3;
|
|
QUERY PLAN
|
|
----------------------------------------------------
|
|
Limit
|
|
-> Index Only 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
|
|
-189.02386 | 10.023865
|
|
-158.17741 | 20.822586
|
|
(3 rows)
|
|
|