Bug #103489 Different result for enum index

• Submitted: 27 Apr 2021 3:45
• Modified: 27 Apr 2021 6:38
• Reporter: Shenghui Wu
• Status: Verified
• Category: MySQL Server: Optimizer
• Severity: S3 (Non-critical)
• Version: 8.0.22, 5.7.34, 8.0.24, 8.0.29, 5.7.37
• OS: Any
• CPU Architecture: Any

[27 Apr 2021 3:45] Shenghui Wu

Description:
Different result between using enum index or not.

How to repeat:
drop table t;
create table t(e enum(""));
insert ignore into t values(0),(1);
select * from t where e = "";
MySQL [test]> select * from t where e = "";
+------+
| e    |
+------+
|      |
|      |
+------+
2 rows in set (0.000 sec)

alter table t add index idx(e);
select * from t where e = "";
MySQL [test]> select * from t where e = "";
+------+
| e    |
+------+
|      |
+------+
1 row in set (0.001 sec)

[27 Apr 2021 6:38] MySQL Verification Team

Hello Shenghui Wu,

Thank you for the report and test case.

regards,
Umesh