Missing double overflow error exception in Tiflash

[curry-oss]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

Drop table if exists t1;
CREATE TABLE t1 (
    id INT PRIMARY KEY AUTO_INCREMENT
);

ALTER TABLE t1 SET TIFLASH REPLICA 1;
INSERT INTO t1 values (1000);

SELECT /*+ READ_FROM_STORAGE(TIKV[t1])*/
    EXP(id) AS exp_overflow
FROM
    t1;

SELECT /*+ READ_FROM_STORAGE(TIFLASH[t1])*/
    EXP(id) AS exp_overflow
FROM
    t1;

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

I find that the returned information is inconsistent across two queries.

3. What did you see instead (Required)

mysql> SELECT /*+ READ_FROM_STORAGE(TIFLASH[t1])*/     EXP(id) AS exp_overflow FROM     t1;
+--------------+
| exp_overflow |
+--------------+
|            0 |
+--------------+
1 row in set (0.04 sec)

mysql> SELECT /*+ READ_FROM_STORAGE(TIKV[t1])*/     EXP(id) AS exp_overflow FROM     t1;
ERROR 1690 (22003): DOUBLE value is out of range in 'exp(cast(test1.t1.id, double BINARY))'

4. What is your TiDB version? (Required)

TiDB v8.4.0

[curry-oss]

/label affects-8.4

[curry-oss]

/label affects-8.5

[yibin87]

Tiflash currently uses native c++ double type as the implementation. Thus it lacks some overflow checks.

[yibin87]

BTW, are you doing some automatic testing like fuzz to help find tidb issues? @curry-oss

[curry-oss]

Ok, looking forward to it being resolved in the near future.

[curry-oss]

BTW, are you doing some automatic testing like fuzz to help find tidb issues? @curry-oss

I have recently started learning TiDB, but I have not yet used any automated tools.