some data anomalies in read-committed isolation for optimistic transactions
- Dominant language
- Go
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Description
## Bug Report
Please answer these questions before submitting your issue. Thanks!
### 1. Minimal reproduce step (Required)
case 1:
```
set TXN_ISOLATION = read-committed for each session
----------rat_dda_write_read_skew test prepare----------
Q0-T1 execute sql: 'DROP TABLE IF EXISTS t1;'
Q0-T1 execute sql: 'CREATE TABLE t1 (k INT PRIMARY KEY, v INT);'
Q0-T1 execute sql: 'INSERT INTO t1 VALUES (0, 0);'
Q0-T1 execute sql: 'INSERT INTO t1 VALUES (1, 0);'
Q0-T1 execute opt: 'COMMIT';
----------rat_dda_write_read_skew test run----------
Q1-T1 execute sql: 'BEGIN OPTIMISTIC;'
Q2-T1 execute sql: 'UPDATE t1 SET v=1 WHERE k=0;'
Q3-T2 execute sql: 'BEGIN OPTIMISTIC;'
Q4-T2 execute sql: 'UPDATE t1 SET v=1 WHERE k=1;'
Q5-T2 execute sql: 'SELECT * FROM t1 WHERE k=0;'
current_result:
(0,0)
Q6-T1 execute sql: 'SELECT * FROM t1 WHERE k=1; '
current_result:
(1,0)
Q7-T2 execute opt: 'COMMIT';
Q8-T1 execute opt: 'COMMIT';
Q9-T3 execute sql: 'SELECT * FROM t1 ORDER BY k;'
current_result:
(0,1) (1,1)
Q10-T3 execute opt: 'COMMIT';
```
case 2:
```
set TXN_ISOLATION = read-committed for each session
----------rat_dda_write_read_skew_committed test prepare----------
Q0-T1 execute sql: 'DROP TABLE IF EXISTS t1;'
Q0-T1 execute sql: 'CREATE TABLE t1 (k INT PRIMARY KEY, v INT);'
Q0-T1 execute sql: 'INSERT INTO t1 VALUES (0, 0);'
Q0-T1 execute sql: 'INSERT INTO t1 VALUES (1, 0);'
Q0-T1 execute opt: 'COMMIT';
----------rat_dda_write_read_skew_committed test run----------
Q1-T1 execute sql: 'BEGIN OPTIMISTIC;'
Q2-T1 execute sql: 'UPDATE t1 SET v=1 WHERE k=0;'
Q3-T2 execute sql: 'BEGIN OPTIMISTIC;'
Q4-T2 execute sql: 'UPDATE t1 SET v=1 WHERE k=1;'
Q5-T2 execute sql: 'SELECT * FROM t1 WHERE k=0;'
current_result:
(0,0)
Q6-T2 execute opt: 'COMMIT';
Q7-T1 execute sql: 'SELECT * FROM t1 WHERE k=1;'
current_result:
(1,0)
Q8-T1 execute opt: 'COMMIT';
Q9-T3 execute sql: 'SELECT * FROM t1 ORDER BY k;'
current_result:
(0,1) (1,1)
Q10-T3 execute opt: 'COMMIT';
```
case 3:
```
set TXN_ISOLATION = read-committed for each session
----------rat_mda_step_rat test prepare----------
Q0-T1 execute sql: 'DROP TABLE IF EXISTS t1;'
Q0-T1 execute sql: 'CREATE TABLE t1 (k INT PRIMARY KEY, v INT);'
Q0-T1 execute sql: 'INSERT INTO t1 VALUES (0, 0);'
Q0-T1 execute sql: 'INSERT INTO t1 VALUES (1, 0);'
Q0-T1 execute sql: 'INSERT INTO t1 VALUES (2, 0);'
Q0-T1 execute opt: 'COMMIT';
----------rat_mda_step_rat test run----------
Q1-T1 execute sql: 'BEGIN OPTIMISTIC;'
Q2-T1 execute sql: 'UPDATE t1 SET v=1 WHERE k=0;'
Q3-T2 execute sql: 'BEGIN OPTIMISTIC;'
Q4-T2 execute sql: 'UPDATE t1 SET v=1 WHERE k=1;'
Q5-T2 execute sql: 'SELECT * FROM t1 WHERE k=0;'
current_result:
(0,0)
Q6-T3 execute sql: 'BEGIN OPTIMISTIC;'
Q7-T3 execute sql: 'UPDATE t1 SET v=1 WHERE k=2;'
Q8-T3 execute sql: 'SELECT * FROM t1 WHERE k=1;'
current_result:
(1,0)
Q9-T1 execute sql: 'SELECT * FROM t1 WHERE k=2;'
current_result:
(2,0)
Q10-T1 execute opt: 'COMMIT';
Q11-T2 execute opt: 'COMMIT';
Q12-T3 execute opt: 'COMMIT';
Q13-T4 execute sql: 'SELECT * FROM t1 ORDER BY k;'
current_result:
(0,1) (1,1) (2,1)
Q14-T4 execute opt: 'COMMIT';
```
case 4:
```
set TXN_ISOLATION = read-committed for each session
----------iat_dda_write_skew test prepare----------
Q0-T1 execute sql: 'DROP TABLE IF EXISTS t1;'
Q0-T1 execute sql: 'CREATE TABLE t1 (k INT PRIMARY KEY, v INT);'
Q0-T1 execute sql: 'INSERT INTO t1 VALUES (0, 0);'
Q0-T1 execute sql: 'INSERT INTO t1 VALUES (1, 0);'
Q0-T1 execute opt: 'COMMIT';
----------iat_dda_write_skew test run----------
Q1-T1 execute sql: 'BEGIN OPTIMISTIC;'
Q2-T1 execute sql: 'SELECT * FROM t1 WHERE k=0; '
current_result:
(0,0)
Q3-T2 execute sql: 'BEGIN OPTIMISTIC;'
Q4-T2 execute sql: 'SELECT * FROM t1 WHERE k=1;'
current_result:
(1,0)
Q5-T2 execute sql: 'UPDATE t1 SET v=1 WHERE k=0;'
Q6-T1 execute sql: 'UPDATE t1 SET v=1 WHERE k=1;'
Q7-T1 execute opt: 'COMMIT';
Q8-T2 execute opt: 'COMMIT';
Q9-T3 execute sql: 'SELECT * FROM t1 ORDER BY k;'
current_result:
(0,1) (1,1)
Q8-T3 execute opt: 'COMMIT';
```
case 5:
```
set TXN_ISOLATION = read-committed for each session
----------iat_dda_write_skew_committed test prepare----------
Q0-T1 execute sql: 'DROP TABLE IF EXISTS t1;'
Q0-T1 execute sql: 'CREATE TABLE t1 (k INT PRIMARY KEY, v INT);'
Q0-T1 execute sql: 'INSERT INTO t1 VALUES (0, 0);'
Q0-T1 execute sql: 'INSERT INTO t1 VALUES (1, 0);'
Q0-T1 execute opt: 'COMMIT';
----------iat_dda_write_skew_committed test run----------
Q1-T1 execute sql: 'BEGIN OPTIMISTIC;'
Q2-T1 execute sql: 'SELECT * FROM t1 WHERE k=0; '
current_result:
(0,0)
Q3-T2 execute sql: 'BEGIN OPTIMISTIC;'
Q4-T2 execute sql: 'SELECT * FROM t1 WHERE k=1;'
current_result:
(1,0)
Q5-T2 execute sql: 'UPDATE t1 SET v=1 WHERE k=0;'
Q6-T2 execute opt: 'COMMIT';
Q7-T1 execute sql: 'UPDATE t1 SET v=1 WHERE k=1;'
Q8-T1 execute opt: 'COMMIT';
Q9-T3 execute sql: 'SELECT * FROM t1 ORDER BY k;'
current_result:
(0,1) (1,1)
Q10-T3 execute opt: 'COMMIT';
```
case 6:
```
set TXN_ISOLATION = read-committed for each session
----------iat_mda_step_iat test prepare----------
Q0-T1 execute sql: 'DROP TABLE IF EXISTS t1;'
Q0-T1 execute sql: 'CREATE TABLE t1 (k INT PRIMARY KEY, v INT);'
Q0-T1 execute sql: 'INSERT INTO t1 VALUES (0, 0);'
Q0-T1 execute sql: 'INSERT INTO t1 VALUES (1, 0);'
Q0-T1 execute sql: 'INSERT INTO t1 VALUES (2, 0);'
Q0-T1 execute opt: 'COMMIT';
----------iat_mda_step_iat test run----------
Q1-T1 execute sql: 'BEGIN OPTIMISTIC;'
Q2-T1 execute sql: 'SELECT * FROM t1 WHERE k=2;'
current_result:
(2,0)
Q3-T2 execute sql: 'BEGIN OPTIMISTIC;'
Q4-T2 execute sql: 'SELECT * FROM t1 WHERE k=0;'
current_result:
(0,0)
Q5-T3 execute sql: 'BEGIN OPTIMISTIC;'
Q6-T3 execute sql: 'SELECT * FROM t1 WHERE k=1;'
current_result:
(1,0)
Q7-T1 execute sql: 'UPDATE t1 SET v=1 WHERE k=0;'
Q8-T2 execute sql: 'UPDATE t1 SET v=1 WHERE k=1;'
Q9-T3 execute sql: 'UPDATE t1 SET v=1 WHERE k=2;'
Q10-T1 execute opt: 'COMMIT';
Q11-T2 execute opt: 'COMMIT';
Q12-T3 execute opt: 'COMMIT';
Q13-T4 execute sql: 'SELECT * FROM t1 ORDER BY k;'
current_result:
(0,1) (1,1) (2,1)
Q14-T4 execute opt: 'COMMIT';
```
### 2. What did you expect to see? (Required)
All transactions commit successfully.
### 3. What did you see instead (Required)
One of the transactions should be aborted.
### 4. What is your TiDB version? (Required)
v5.4.0
Contributor guide
Assessment
This issue has not been assessed yet.