-- 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)