1-- Test bitmap AND and OR
2
3
4-- Generate enough data that we can test the lossy bitmaps.
5
6-- There's 55 tuples per page in the table. 53 is just
7-- below 55, so that an index scan with qual a = constant
8-- will return at least one hit per page. 59 is just above
9-- 55, so that an index scan with qual b = constant will return
10-- hits on most but not all pages. 53 and 59 are prime, so that
11-- there's a maximum number of a,b combinations in the table.
12-- That allows us to test all the different combinations of
13-- lossy and non-lossy pages with the minimum amount of data
14
15CREATE TABLE bmscantest (a int, b int, t text);
16
17INSERT INTO bmscantest
18  SELECT (r%53), (r%59), 'foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo'
19  FROM generate_series(1,70000) r;
20
21CREATE INDEX i_bmtest_a ON bmscantest(a);
22CREATE INDEX i_bmtest_b ON bmscantest(b);
23
24-- We want to use bitmapscans. With default settings, the planner currently
25-- chooses a bitmap scan for the queries below anyway, but let's make sure.
26set enable_indexscan=false;
27set enable_seqscan=false;
28
29-- Lower work_mem to trigger use of lossy bitmaps
30set work_mem = 64;
31
32
33-- Test bitmap-and.
34SELECT count(*) FROM bmscantest WHERE a = 1 AND b = 1;
35
36-- Test bitmap-or.
37SELECT count(*) FROM bmscantest WHERE a = 1 OR b = 1;
38
39
40-- clean up
41DROP TABLE bmscantest;
42