84. SELECT age
FROM users
WHERE id=1
T1 T2 DB
1, 20
120
UPDATE users
SET age=21
where id=1
SELECT age
FROM users
WHERE id=1
85. SELECT age
FROM users
WHERE id=1
T1 T2 DB
1, 20
120
UPDATE users
SET age=21
where id=1
T1 Snapshot
1, 20
SELECT age
FROM users
WHERE id=1
86. SELECT age
FROM users
WHERE id=1
T1 T2 DB
1, 21
120
UPDATE users
SET age=21
where id=1
2
T1 Snapshot
1, 20
SELECT age
FROM users
WHERE id=1
87. SELECT age
FROM users
WHERE id=1
T1 T2 DB
1, 21
120
UPDATE users
SET age=21
where id=1
T1 Snapshot
1, 20 2
어
스냅샷이
20이네?
3
SELECT age
FROM users
WHERE id=1
88. SELECT age
FROM users
WHERE id=1
T1 T2
SELECT age
FROM users
WHERE id=1
DB
1, 21
120
UPDATE users
SET age=21
where id=1
T1 Snapshot
1, 20 2
그럼 20
디비가 뭐라든…
20 3
102. SELECT age
FROM users
WHERE id=1
T1 T2
SELECT age
FROM users
WHERE id=1
DB
1, 20
UPDATE users
SET age=21
where id=1
ROLLBACK
103. SELECT age
FROM users
WHERE id=1
T1 T2
SELECT age
FROM users
WHERE id=1
DB
1, 20
120
UPDATE users
SET age=21
where id=1
ROLLBACK
104. SELECT age
FROM users
WHERE id=1
T1 T2
SELECT age
FROM users
WHERE id=1
DB
1, 20
120
UPDATE users
SET age=21
where id=1
ROLLBACK
2
105. SELECT age
FROM users
WHERE id=1
T1 T2
SELECT age
FROM users
WHERE id=1
DB
1, 20
120
UPDATE users
SET age=21
where id=1
2
ROLLBACK
어 우리 커밋 안했는데
기다려야하는거 아니에요?
몰라 대충 넣어
106. SELECT age
FROM users
WHERE id=1
T1 T2 DB
1, 21
120
UPDATE users
SET age=21
where id=1
ROLLBACK
2
SELECT age
FROM users
WHERE id=1
21
3
107. SELECT age
FROM users
WHERE id=1
T1 T2
SELECT age
FROM users
WHERE id=1
DB
1, 21
120
UPDATE users
SET age=21
where id=1
2
21
3
ROLLBACK
4
108. SELECT age
FROM users
WHERE id=1
T1 T2
SELECT age
FROM users
WHERE id=1
DB
1, 20
120
UPDATE users
SET age=21
where id=1
2
21
3
ROLLBACK
4
롤백롤백
109. SELECT age
FROM users
WHERE id=1
T1 T2
SELECT age
FROM users
WHERE id=1
DB
1, 20
120
UPDATE users
SET age=21
where id=1
2
21
3
ROLLBACK
4
롤백롤백
????????