1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
|
-- bit check
CREATE TABLE bittmp (a bit(33));
\copy bittmp from 'data/bit.data'
SET enable_seqscan=on;
SELECT count(*) FROM bittmp WHERE a < '011011000100010111011000110000100';
count
-------
249
(1 row)
SELECT count(*) FROM bittmp WHERE a <= '011011000100010111011000110000100';
count
-------
250
(1 row)
SELECT count(*) FROM bittmp WHERE a = '011011000100010111011000110000100';
count
-------
1
(1 row)
SELECT count(*) FROM bittmp WHERE a >= '011011000100010111011000110000100';
count
-------
351
(1 row)
SELECT count(*) FROM bittmp WHERE a > '011011000100010111011000110000100';
count
-------
350
(1 row)
CREATE INDEX bitidx ON bittmp USING GIST ( a );
SET enable_seqscan=off;
SELECT count(*) FROM bittmp WHERE a < '011011000100010111011000110000100';
count
-------
249
(1 row)
SELECT count(*) FROM bittmp WHERE a <= '011011000100010111011000110000100';
count
-------
250
(1 row)
SELECT count(*) FROM bittmp WHERE a = '011011000100010111011000110000100';
count
-------
1
(1 row)
SELECT count(*) FROM bittmp WHERE a >= '011011000100010111011000110000100';
count
-------
351
(1 row)
SELECT count(*) FROM bittmp WHERE a > '011011000100010111011000110000100';
count
-------
350
(1 row)
-- Test index-only scans
SET enable_bitmapscan=off;
EXPLAIN (COSTS OFF)
SELECT a FROM bittmp WHERE a BETWEEN '1000000' and '1000001';
QUERY PLAN
---------------------------------------------------------------------
Index Only Scan using bitidx on bittmp
Index Cond: ((a >= '1000000'::"bit") AND (a <= '1000001'::"bit"))
(2 rows)
|
