In function returned incorrect result when in-list contains two arguments and one is column

[yibin87]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

mysql> create table a (col0 integer, col1 integer);
mysql> insert into a values(20, 30);
mysql> insert into a values(40, 50);
mysql> insert into a values(null, null);
mysql> alter table a set tiflash replica 1;
mysql> set session tidb_isolation_read_engines='tiflash';
mysql> select * from a where col0 in (null, col0);

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

+------+------+
| col0 | col1 |
+------+------+
| 20 | 30 |
| 40 | 50 |
+------+------+

3. What did you see instead (Required)

Empty set.

4. What is your TiFlash version? (Required)

master, commit hash: 6918946

[yibin87]

v.7.4.0 reproduced this issue.

[yibin87]

May need to run set session tidb_isolation_read_engines='tikv'; set session tidb_isolation_read_engines='tiflash'; several times to reproduce this issue.

[yibin87]

From explain analyze results, it seems RSFilter filters all rows:

mysql> explain analyze select * from a where col0 in (null, col0);

+----------------------------+---------+---------+--------------+---------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------+-----------+------+
| id                         | estRows | actRows | task         | access object | execution info                                                                                                                                                                                                                                                                                                                                                                                                          | operator info                                            | memory    | disk |
+----------------------------+---------+---------+--------------+---------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------+-----------+------+
| TableReader_13             | 2.40    | 0       | root         |               | time:7.57ms, loops:1, RU:0.000000, cop_task: {num: 1, max: 0s, proc_keys: 0, copr_cache_hit_ratio: 0.00}                                                                                                                                                                                                                                                                                                                | MppVersion: 2, data:ExchangeSender_12                    | 305 Bytes | N/A  |
| └─ExchangeSender_12        | 2.40    | 0       | mpp[tiflash] |               | tiflash_task:{time:5.96ms, loops:0, threads:8}                                                                                                                                                                                                                                                                                                                                                                          | ExchangeType: PassThrough                                | N/A       | N/A  |
|   └─Selection_11           | 2.40    | 0       | mpp[tiflash] |               | tiflash_task:{time:5.79ms, loops:0, threads:8}                                                                                                                                                                                                                                                                                                                                                                          | in(test.a.col0, NULL, test.a.col0)                       | N/A       | N/A  |
|     └─TableFullScan_10     | 3.00    | 0       | mpp[tiflash] | table:a       | tiflash_task:{time:5.79ms, loops:0, threads:8}, tiflash_scan:{dtfile:{total_scanned_packs:0, total_skipped_packs:1, total_scanned_rows:0, total_skipped_rows:3, total_rs_index_check_time: 0ms, total_read_time: 0ms, total_disagg_read_cache_hit_size: 0, total_disagg_read_cache_miss_size: 0}, total_create_snapshot_time: 0ms, total_local_region_num: 1, total_remote_region_num: 0, total_learner_read_time: 0ms} | pushed down filter:empty, keep order:false, stats:pseudo | N/A       | N/A  |
+----------------------------+---------+---------+--------------+---------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------+-----------+------+
4 rows in set (0.01 sec)