incorrect result while part or condition expr failed

[aytrack]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

deploy a cluster with tikv

create table t2 (a bigint unsigned);
insert into t2 values (18446744073709551615);
select * from t2 where a > 10 or a  + 10 >= 18446744073709551615 + 10;

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

MySQL test> select * from t2 where a > 10 or a  + 10 >= 18446744073709551615 + 10;
+----------------------+
| a                    |
+----------------------+
| 18446744073709551615 |
+----------------------+

3. What did you see instead (Required)

MySQL root@172.16.5.105:test> select * from t2 where a > 10 or a  + 10 >= 18446744073709551615 + 10;
(1690, "BIGINT UNSIGNED value is out of range in '(10 + -1)'")

4. What is your TiDB version? (Required)

release-5.1: 7784454
master: aaed434

[fuzhe1989]

any update? @lzmhhh123

[lzmhhh123]

This is because when eval condition a > 10 or a + 10 >= 18446744073709551615 + 10. TiDB only execute a > 10 then assets the condition is ture. But coprocessor must execute a > 10 and a+10 >= 18446744073709551615 + 10 both. So the tikv rises the error.

[fuzhe1989]

tiflash doesn't have this issue.

[XuHuaiyu]

TiDB and TiKV both have the problem.

[fuzhe1989]

/assign @XuHuaiyu

[yibin87]

Try mysql, it seems in some cases, it will also execute the second comparison and report an overflow error:
mysql> select * from t2 where a > 10 or a >= 18446744073709551615 + 10;
ERROR 1690 (22003): BIGINT UNSIGNED value is out of range in '(18446744073709551615 + 10)'
So overflow calculations => ERROR seems reasonable.
The real problems may be

1. Inconsistency between tidb and tiflash
2. The TiDB error message: '(10 + -1)', converting BigInt Unsigned to BigInt, not user friendly.

[XuHuaiyu]

Confirmed in TiDB with and without pushing down "or", both cases work successfully.

[yibin87]

Confirmed in TiDB with and without pushing down "or", both cases work successfully.

You mean, TiDB won't report error message in the latest version for this case? @XuHuaiyu

[fuzhe1989]

@yibin87 Huaiyu means TiDB itself won't report error message in such case. Neither during constant-folding nor the execution of logical-or function (TiDB version). Actually it's the TiKV reported the error.