PostgreSQL - Tuples Demo

CREATE TABLE ItaiTable ( ItaiID INT4, Name VARCHAR(32) );

SELECT * FROM pgstattuple('itaitable’);

INSERT INTO ItaiTable (ItaiID, Name) VALUES (1, 'Itai’);

INSERT INTO ItaiTable (ItaiID, Name) VALUES (2, 'Yossi’);

SELECT relname, n_live_tup, n_dead_tup,

n_tup_ins, n_tup_upd, n_tup_del, vacuum_count

FROM pg_stat_user_tables WHERE relname = 'itaitable’;

UPDATE ItaiTable SET Name = 'Anat' WHERE ItaiID = 1;

UPDATE ItaiTable SET Name = 'Vitaly' WHERE ItaiID = 1;

DELETE FROM ItaiTable WHERE ItaiID = 1;

SELECT * FROM ItaiTable;

VACUUM ItaiTable;

SELECT * FROM heap_page_items(get_raw_page('itaitable', 0));

VACUUM FULL ItaiTable;

    -- FULL = allocate the unused space back to the operating system

SELECT * FROM heap_page_items(get_raw_page('itaitable', 0));