planner: same plans with different in-list should have the same plan digests

[qw4990]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

tiup playground  --db 1  --kv 1 --tiflash 0 nightly

create table t (a int);

select * from t where a in (1, 2);
select * from t where a in (1, 2, 3);
select * from t where a in (1, 2, 3, 4);
select * from t where a in (1, 2, 3, 4, 5);
select * from t where a in (1, 2, 3, 4, 5, 6);
select * from t where a in (1, 2, 3, 4, 5, 6, 7);

These queries and plans are the same, but the Dashboard is flooded with different plans, which significantly affect the user experience:

The root cause is that they have different plan digest, we need to update our plan digest algorithm to ignore different length of in-list:

mysql> select DIGEST_TEXT, DIGEST, PLAN_DIGEST from STATEMENTS_SUMMARY where DIGEST='27b5708e7f94f1ad32ba9ef1475f1a9c0225444f97f5d495f7d642182635e9d0';
+----------------------------------------+------------------------------------------------------------------+------------------------------------------------------------------+
| DIGEST_TEXT                            | DIGEST                                                           | PLAN_DIGEST                                                      |
+----------------------------------------+------------------------------------------------------------------+------------------------------------------------------------------+
| select * from `t` where `a` in ( ... ) | 27b5708e7f94f1ad32ba9ef1475f1a9c0225444f97f5d495f7d642182635e9d0 | 35c33c6a4ce69189ba638adc43b84513811732513665bb3a805e4ab888360de9 |
| select * from `t` where `a` in ( ... ) | 27b5708e7f94f1ad32ba9ef1475f1a9c0225444f97f5d495f7d642182635e9d0 | 23ea30430e8bd8c0845e8fabceb217e98a743dc0a3b42e63555abd39cb77ccf6 |
| select * from `t` where `a` in ( ... ) | 27b5708e7f94f1ad32ba9ef1475f1a9c0225444f97f5d495f7d642182635e9d0 | 32da2ca4acd7d0536a2da4a59c8e9e5c75088dbb1e87a76e07646fafe5652ce9 |
| select * from `t` where `a` in ( ... ) | 27b5708e7f94f1ad32ba9ef1475f1a9c0225444f97f5d495f7d642182635e9d0 | 59a89207acb798c0400404a3bc47df2147370b7dea3765afc37f8f27f3ff0e0e |
| select * from `t` where `a` in ( ... ) | 27b5708e7f94f1ad32ba9ef1475f1a9c0225444f97f5d495f7d642182635e9d0 | ddbf412c92228a757994b14210801d86f61eb9b510e6bc36dca75d5d4151ad02 |
| select * from `t` where `a` in ( ... ) | 27b5708e7f94f1ad32ba9ef1475f1a9c0225444f97f5d495f7d642182635e9d0 | 01308613e49648a4431351439f0596ce1236bc671f9ced66c04bc19b2b8b2c38 |
+----------------------------------------+------------------------------------------------------------------+------------------------------------------------------------------+
6 rows in set (0.002 sec)

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

3. What did you see instead (Required)

4. What is your TiDB version? (Required)

Master

[qw4990]

Enabling tidb_ignore_inlist_plan_digest can solve this problem, but we need to enable it by default.

[qw4990]

Duplicated with #33559 and solved by #47216