clustered index + new collation + union panic

[wjhuang2016]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

mysql> show create table t;

+-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table                                                                                                                                                                                                                                                  |
+-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| t     | CREATE TABLE `t` (
  `a` char(10) COLLATE utf8mb4_unicode_ci NOT NULL,
  `b` char(20) COLLATE utf8mb4_general_ci NOT NULL,
  `c` int(11) NOT NULL,
  PRIMARY KEY (`a`,`b`,`c`),
  KEY `idx` (`a`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin |
+-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> select * from t;
+---+---+----+
| a | b | c  |
+---+---+----+
| # | C | 10 |
| $ | c | 20 |
| $ | c | 30 |
| a | a | 10 |
| A | A | 30 |
+---+---+----+
5 rows in set (0.00 sec)

mysql> select * from t where a="#" UNION select * from t where a="$";
ERROR 1105 (HY000): runtime error: index out of range [2] with length 2

2. What did you expect to see? (Required)

Right result

3. What did you see instead (Required)

Panic

4. What is your TiDB version? (Required)

master

[wjhuang2016]

UNION is not needed.

mysql> select * from t where a="#"
ERROR 1105 (HY000): runtime error: index out of range [2] with length 2

[qw4990]

@wjhuang2016 I cannot reproduce this problem now. Could you please confirm it again?

[lzmhhh123]

Hi, clustered index related issues should be maintained the severity to major. It doesn't affect the release branch.

[ti-srebot]

Please edit this comment or add a new comment to complete the following information

Not a bug

1. Remove the 'type/bug' label
2. Add notes to indicate why it is not a bug

Duplicate bug

1. Add the 'type/duplicate' label
2. Add the link to the original bug

Bug

Note: Make Sure that 'component', and 'severity' labels are added
Example for how to fill out the template: #20100

1. Root Cause Analysis (RCA) (optional)

2. Symptom (optional)

3. All Trigger Conditions (optional)

4. Workaround (optional)

5. Affected versions

master

6. Fixed versions

master