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-rw-r--r--src/test/regress/sql/random.sql44
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diff --git a/src/test/regress/sql/random.sql b/src/test/regress/sql/random.sql
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+--
+-- RANDOM
+-- Test the random function
+--
+
+-- count the number of tuples originally, should be 1000
+SELECT count(*) FROM onek;
+
+-- pick three random rows, they shouldn't match
+(SELECT unique1 AS random
+ FROM onek ORDER BY random() LIMIT 1)
+INTERSECT
+(SELECT unique1 AS random
+ FROM onek ORDER BY random() LIMIT 1)
+INTERSECT
+(SELECT unique1 AS random
+ FROM onek ORDER BY random() LIMIT 1);
+
+-- count roughly 1/10 of the tuples
+CREATE TABLE RANDOM_TBL AS
+ SELECT count(*) AS random
+ FROM onek WHERE random() < 1.0/10;
+
+-- select again, the count should be different
+INSERT INTO RANDOM_TBL (random)
+ SELECT count(*)
+ FROM onek WHERE random() < 1.0/10;
+
+-- select again, the count should be different
+INSERT INTO RANDOM_TBL (random)
+ SELECT count(*)
+ FROM onek WHERE random() < 1.0/10;
+
+-- select again, the count should be different
+INSERT INTO RANDOM_TBL (random)
+ SELECT count(*)
+ FROM onek WHERE random() < 1.0/10;
+
+-- now test that they are different counts
+SELECT random, count(random) FROM RANDOM_TBL
+ GROUP BY random HAVING count(random) > 3;
+
+SELECT AVG(random) FROM RANDOM_TBL
+ HAVING AVG(random) NOT BETWEEN 80 AND 120;