3. トランザクションIDとは
INSERT INTO r(i) VALUES(1);
INSERT INTO r(i) VALUES(2);
INSERT INTO r(i) VALUES(3);
SELECT xmin, xmax, i FROM r;
xmin xmax i
664 0 1
665 0 2
666 0 3
4. トランザクションIDとは
INSERT INTO r(i) VALUES(1);
INSERT INTO r(i) VALUES(2);
INSERT INTO r(i) VALUES(3);
SELECT xmin, xmax, i FROM r;
DELETE FROM r WHERE i = 1;
UPDATE r SET i = 4 WHERE i = 2;
xmin xmax i
664 667 1
665 668 2
666 0 3
668 0 4