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|
-- 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)
CREATE INDEX float4idx ON float4tmp USING gist ( a );
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)
|
