index out of range [0] with length 0 when using prepare plan cache

[ChenPeng2013]

Description

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

new_collations_enabled_on_first_bootstrap = true
prepared-plan-cache.enabled = true

CREATE TABLE `t` (
  `c_int` int(11) DEFAULT NULL,
  `c_int2` int(11) GENERATED ALWAYS AS (`c_int` * 2) STORED,
  `c_str` varchar(40) DEFAULT NULL,
  `c_str2` varchar(40) DEFAULT NULL,
  `c_datetime` datetime DEFAULT NULL,
  `c_datetime2` datetime DEFAULT NULL,
  `c_timestamp` timestamp NULL DEFAULT NULL,
  `c_timestamp2` timestamp NULL DEFAULT NULL,
  `c_double` double DEFAULT NULL,
  `c_double2` double DEFAULT NULL,
  `c_decimal` decimal(12,6) DEFAULT NULL,
  KEY `c_int` (`c_int`),
  KEY `c_int2` (`c_int2`),
  KEY `c_str` (`c_str`),
  KEY `c_int_2` (`c_int`,`c_str`),
  KEY `c_decimal` (`c_decimal`),
  KEY `c_datetime` (`c_datetime`),
  UNIQUE KEY `c_datetime2` (`c_datetime2`,`c_datetime`),
  KEY `c_timestamp2` (`c_timestamp2`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;
INSERT INTO `t` (`c_int`, `c_str`, `c_str2`, `c_datetime`, `c_datetime2`, `c_timestamp`, `c_timestamp2`, `c_double`, `c_double2`, `c_decimal`) VALUES (1,'quizzical goldberg','awesome nightingale','2020-05-20 14:06:50','2020-05-21 10:26:58','2020-03-07 13:34:24','2020-01-06 06:32:22',8.120238,93.081973,4.188000),(2,'vibrant moore','mystifying banach','2020-05-05 21:19:18','2020-05-18 19:34:10','2020-02-03 16:00:02','2020-03-24 03:24:59',45.353692,72.942041,8.493000),(5,'vibrant moore','gracious wescoff','2020-03-13 19:59:31','2020-01-13 02:48:57','2020-03-02 16:22:44','2020-04-14 08:43:53',8.698416,88.150439,4.766000),(6,'wizardly wescoff','confident newton','2020-02-06 02:33:38','2020-06-30 01:36:27','2020-06-22 21:57:44','2020-05-19 13:34:38',38.000458,34.614586,7.708000),(7,'hopeful payne','loving antonelli','2020-06-03 18:39:10','2020-01-31 01:28:59','2020-03-17 15:11:55','2020-01-27 16:15:44',76.601025,15.157077,2.327000),(8,'frosty northcutt','crazy engelbart','2020-05-01 18:34:39','2020-02-08 13:09:30','2020-04-17 23:35:29','2020-01-11 13:35:34',61.350777,96.035396,8.166000),(9,'vibrant moore','nostalgic ramanujan','2020-05-29 15:19:55','2020-01-14 07:18:53','2020-04-09 00:17:01','2020-01-19 06:17:37',40.455101,45.393835,7.050000),(10,'funny blackwell','fervent black','2020-06-09 05:57:02','2020-01-30 12:16:00','2020-02-19 20:20:20','2020-03-05 18:40:09',72.813538,96.54546,2.089000),(11,'objective antonelli','inspiring lewin','2020-04-29 08:40:33','2020-01-05 10:44:12','2020-06-06 03:09:58','2020-01-01 05:29:53',34.2709,36.396483,4.910000),(12,'romantic wilbur','intelligent allen','2020-03-17 07:21:10','2020-03-29 08:41:31','2020-03-09 14:41:51','2020-04-20 09:17:40',89.270577,39.561856,5.409000),(13,'stoic galois','flamboyant ritchie','2020-06-13 22:09:30','2020-06-08 19:20:04','2020-06-03 10:14:49','2020-01-09 03:07:06',31.450598,30.61192,1.217000),(15,'reverent yalow','boring ishizaka','2020-01-21 02:05:25','2020-05-07 00:34:24','2020-04-20 21:25:50','2020-05-11 14:47:16',86.941937,37.081463,8.641000);
begin;
update t set c_str = 'goofy ganguly' where c_int = 6 and c_str = 'elated goldberg';
update t set c_str = 'practical blackwell' where c_int = 14 and c_int2 in (27, 3, 16);
update t set c_str = 'romantic turing' where c_int in (16, 9, 21);
update t set c_int = c_int + 10, c_str = 'angry pascal' where c_int in (29, 34);
prepare stmt from "select c_int, c_int2, c_str, c_str2, c_double, c_double2, c_decimal, c_datetime, c_datetime2, c_timestamp, c_timestamp2 from t where c_str = ?";
set @a= 'exciting tesla';
execute stmt using @a;
set@a= 'pensive goldstine';
execute stmt using @a;
insert into t (c_int, c_int2, c_str, c_str2, c_datetime, c_datetime2, c_double, c_double2) values (24, 5, 'focused kepler', 'infallible kowalevski', '2020-01-06 05:29:39', '2020-01-02 12:11:57', 26.587924, 29.212838);
commit;

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

mysql> insert into t (c_int, c_int2, c_str, c_str2, c_datetime, c_datetime2, c_double, c_double2) values (24, 5, 'focused kepler', 'infallible kowalevski', '2020-01-06 05:29:39', '2020-01-02 12:11:57', 26.587924, 29.212838);
ERROR 3105 (HY000): The value specified for generated column 'c_int2' in table 't' is not allowed.
mysql> commit;
Query OK, 0 rows affected (0.00 sec)

3. What did you see instead (Required)

mysql> insert into t (c_int, c_int2, c_str, c_str2, c_datetime, c_datetime2, c_double, c_double2) values (24, 5, 'focused kepler', 'infallible kowalevski', '2020-01-06 05:29:39', '2020-01-02 12:11:57', 26.587924, 29.212838);
ERROR 1105 (HY000): runtime error: index out of range [0] with length 0
mysql> commit;
ERROR 2013 (HY000): Lost connection to MySQL server during query

4. What is your TiDB version? (Required)

Release Version: v4.0.3-62-g3948c7ba7
Edition: Community
Git Commit Hash: 3948c7ba7b5d4a081abf2162b791ab67fe650882
Git Branch: release-4.0
UTC Build Time: 2020-08-12 08:00:18
GoVersion: go1.14.6
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false

SIG slack channel

#sig-exec

Score

• 300

Mentor

• @qw4990

[liuzix]

/label sig/execution

[wjhuang2016]

Minimal reproduced:

mysql> show create table t1;
+-------+-----------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table                                                                                                                            |
+-------+-----------------------------------------------------------------------------------------------------------------------------------------+
| t1    | CREATE TABLE `t1` (
  `a` char(10) DEFAULT NULL,
  `b` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin |
+-------+-----------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> begin;
Query OK, 0 rows affected (0.00 sec)

mysql> prepare stmt from "select a, b from t1 where a=?";
Query OK, 0 rows affected (0.00 sec)

mysql> set @a="aaa";
Query OK, 0 rows affected (0.00 sec)

mysql> execute stmt using @a;
Empty set (0.00 sec)

mysql> insert into t1 values("abc", 3, 5);
ERROR 1105 (HY000): runtime error: index out of range [0] with length 0  

[bb7133]

PTAL @SunRunAway

[SunRunAway]

@eurekaka PTAL

[SunRunAway]

Besides, tidb-server is needed to be avoided to be killed by this panic.

[sre-bot]

Integrity check:
RCA symptom trigger_condition affect_version fix_version fields are empty
@eurekaka
Please comment /info to get template

[ti-srebot]

Please edit this 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)

If a query raises error before storing its plan into session.currentPlan, e.g, error happens in optimizer, then the session.currentPlan is not updated, i.e, it is the plan for the former query, so after returned to dispatch -> SetProcessInfo, the plan is accessed again, while the params have already gone, so panic happens.

2. Symptom

When plan cache is enabled, users may see panic for a query.

3. All Trigger Conditions

• plan cache is enabled
• a query may report error in the optimizer stage

4. Workaround (optional)

Disable plan cache.

5. Affected versions

unreleased

6. Fixed versions

v4.0.8