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set enable_seqscan=off;
CREATE TABLE test_bpchar (
i char(10)
);
INSERT INTO test_bpchar VALUES ('a'),('ab'),('abc'),('abc '),('abb'),('axy'),('xyz'),('xyz ');
CREATE INDEX idx_bpchar ON test_bpchar USING gin (i);
SELECT * FROM test_bpchar WHERE i<'abc' ORDER BY i;
i
------------
a
ab
abb
(3 rows)
SELECT * FROM test_bpchar WHERE i<='abc' ORDER BY i;
i
------------
a
ab
abb
abc
abc
(5 rows)
SELECT * FROM test_bpchar WHERE i='abc' ORDER BY i;
i
------------
abc
abc
(2 rows)
SELECT * FROM test_bpchar WHERE i='abc ' ORDER BY i;
i
------------
abc
abc
(2 rows)
SELECT * FROM test_bpchar WHERE i>='abc' ORDER BY i;
i
------------
abc
abc
axy
xyz
xyz
(5 rows)
SELECT * FROM test_bpchar WHERE i>'abc' ORDER BY i;
i
------------
axy
xyz
xyz
(3 rows)
EXPLAIN (COSTS OFF) SELECT * FROM test_bpchar WHERE i<'abc' ORDER BY i;
QUERY PLAN
-----------------------------------------------
Sort
Sort Key: i
-> Bitmap Heap Scan on test_bpchar
Recheck Cond: (i < 'abc'::bpchar)
-> Bitmap Index Scan on idx_bpchar
Index Cond: (i < 'abc'::bpchar)
(6 rows)
EXPLAIN (COSTS OFF) SELECT * FROM test_bpchar WHERE i<='abc' ORDER BY i;
QUERY PLAN
------------------------------------------------
Sort
Sort Key: i
-> Bitmap Heap Scan on test_bpchar
Recheck Cond: (i <= 'abc'::bpchar)
-> Bitmap Index Scan on idx_bpchar
Index Cond: (i <= 'abc'::bpchar)
(6 rows)
EXPLAIN (COSTS OFF) SELECT * FROM test_bpchar WHERE i='abc' ORDER BY i;
QUERY PLAN
-----------------------------------------
Bitmap Heap Scan on test_bpchar
Recheck Cond: (i = 'abc'::bpchar)
-> Bitmap Index Scan on idx_bpchar
Index Cond: (i = 'abc'::bpchar)
(4 rows)
EXPLAIN (COSTS OFF) SELECT * FROM test_bpchar WHERE i>='abc' ORDER BY i;
QUERY PLAN
------------------------------------------------
Sort
Sort Key: i
-> Bitmap Heap Scan on test_bpchar
Recheck Cond: (i >= 'abc'::bpchar)
-> Bitmap Index Scan on idx_bpchar
Index Cond: (i >= 'abc'::bpchar)
(6 rows)
EXPLAIN (COSTS OFF) SELECT * FROM test_bpchar WHERE i>'abc' ORDER BY i;
QUERY PLAN
-----------------------------------------------
Sort
Sort Key: i
-> Bitmap Heap Scan on test_bpchar
Recheck Cond: (i > 'abc'::bpchar)
-> Bitmap Index Scan on idx_bpchar
Index Cond: (i > 'abc'::bpchar)
(6 rows)
|
