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