-- clear out heap file
TRUNCATE mvcc_demo;

VACUUM mvcc_demo;

SELECT pg_freespace('mvcc_demo');

INSERT INTO mvcc_demo VALUES (1);

VACUUM mvcc_demo;

SELECT pg_freespace('mvcc_demo');

INSERT INTO mvcc_demo VALUES (2);

VACUUM mvcc_demo;

SELECT pg_freespace('mvcc_demo');

INSERT INTO mvcc_demo VALUES (3);

VACUUM mvcc_demo;

SELECT pg_freespace('mvcc_demo');

DELETE FROM mvcc_demo WHERE val = 3;

VACUUM mvcc_demo;

SELECT pg_freespace('mvcc_demo');

DELETE FROM mvcc_demo WHERE val = 2;

VACUUM mvcc_demo;

SELECT pg_freespace('mvcc_demo');

SELECT * FROM mvcc_demo_page0;

DELETE FROM mvcc_demo WHERE val = 1;

VACUUM mvcc_demo;

SELECT pg_freespace('mvcc_demo');

VACUUM mvcc_demo;

SELECT pg_relation_size('mvcc_demo');