char.out

-- char check
CREATE TABLE chartmp (a char(32));
\copy chartmp from 'data/char.data'
SET enable_seqscan=on;
SELECT count(*) FROM chartmp WHERE a <   '31b0'::char(32);
 count 
-------
   587
(1 row)

SELECT count(*) FROM chartmp WHERE a <=  '31b0'::char(32);
 count 
-------
   588
(1 row)

SELECT count(*) FROM chartmp WHERE a  =  '31b0'::char(32);
 count 
-------
     1
(1 row)

SELECT count(*) FROM chartmp WHERE a >=  '31b0'::char(32);
 count 
-------
   401
(1 row)

SELECT count(*) FROM chartmp WHERE a >   '31b0'::char(32);
 count 
-------
   400
(1 row)

CREATE INDEX charidx ON chartmp USING GIST ( a );
SET enable_seqscan=off;
SELECT count(*) FROM chartmp WHERE a <   '31b0'::char(32);
 count 
-------
   587
(1 row)

SELECT count(*) FROM chartmp WHERE a <=  '31b0'::char(32);
 count 
-------
   588
(1 row)

SELECT count(*) FROM chartmp WHERE a  =  '31b0'::char(32);
 count 
-------
     1
(1 row)

SELECT count(*) FROM chartmp WHERE a >=  '31b0'::char(32);
 count 
-------
   401
(1 row)

SELECT count(*) FROM chartmp WHERE a >   '31b0'::char(32);
 count 
-------
   400
(1 row)

-- Test index-only scans
SET enable_bitmapscan=off;
EXPLAIN (COSTS OFF)
SELECT * FROM chartmp WHERE a BETWEEN '31a' AND '31c';
                             QUERY PLAN                              
---------------------------------------------------------------------
 Remote Fast Query Execution
   Node/s: datanode_1, datanode_2
   ->  Index Only Scan using charidx on chartmp
         Index Cond: ((a >= '31a'::bpchar) AND (a <= '31c'::bpchar))
(4 rows)

SELECT * FROM chartmp WHERE a BETWEEN '31a' AND '31c';
  a   
------
 31b0
(1 row)