CREATE TABLE clustertest (key int PRIMARY KEY);
INSERT INTO clustertest VALUES (10);
INSERT INTO clustertest VALUES (20);
INSERT INTO clustertest VALUES (30);
INSERT INTO clustertest VALUES (40);
INSERT INTO clustertest VALUES (50);
-- Use a transaction so that updates are not committed when CLUSTER sees 'em
BEGIN;
-- Test update where the old row version is found first in the scan
UPDATE clustertest SET key = 100 WHERE key = 10;
-- Test update where the new row version is found first in the scan
UPDATE clustertest SET key = 35 WHERE key = 40;
-- Test longer update chain
UPDATE clustertest SET key = 60 WHERE key = 50;
UPDATE clustertest SET key = 70 WHERE key = 60;
UPDATE clustertest SET key = 80 WHERE key = 70;
SELECT * FROM clustertest;
 
CLUSTER clustertest_pkey ON clustertest;
SELECT * FROM clustertest;