chore: import upstream snapshot with attribution

testing/go/regression/tests/bitmapops.sql

@@ -0,0 +1,41 @@
+-- Test bitmap AND and OR
+
+
+-- Generate enough data that we can test the lossy bitmaps.
+
+-- There's 55 tuples per page in the table. 53 is just
+-- below 55, so that an index scan with qual a = constant
+-- will return at least one hit per page. 59 is just above
+-- 55, so that an index scan with qual b = constant will return
+-- hits on most but not all pages. 53 and 59 are prime, so that
+-- there's a maximum number of a,b combinations in the table.
+-- That allows us to test all the different combinations of
+-- lossy and non-lossy pages with the minimum amount of data
+
+CREATE TABLE bmscantest (a int, b int, t text);
+
+INSERT INTO bmscantest
+  SELECT (r%53), (r%59), 'foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo'
+  FROM generate_series(1,70000) r;
+
+CREATE INDEX i_bmtest_a ON bmscantest(a);
+CREATE INDEX i_bmtest_b ON bmscantest(b);
+
+-- We want to use bitmapscans. With default settings, the planner currently
+-- chooses a bitmap scan for the queries below anyway, but let's make sure.
+set enable_indexscan=false;
+set enable_seqscan=false;
+
+-- Lower work_mem to trigger use of lossy bitmaps
+set work_mem = 64;
+
+
+-- Test bitmap-and.
+SELECT count(*) FROM bmscantest WHERE a = 1 AND b = 1;
+
+-- Test bitmap-or.
+SELECT count(*) FROM bmscantest WHERE a = 1 OR b = 1;
+
+
+-- clean up
+DROP TABLE bmscantest;