Explain for Batch_Point_Get does not include partition information in access object

[mjonss]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

create table t (a int primary key, b int, key (b)) partition by hash(a) (partition P0, partition p1, partition P2);
insert into t values (1,1),(2,2),(3,3);
analyze table t;
set @@tidb_partition_prune_mode = 'static';
explain select * from t where a IN (1,2);
explain select * from t where a = 1 OR a = 2;
set @@tidb_partition_prune_mode = 'dynamic';
explain select * from t where a IN (1,2);
explain select * from t where a = 1 OR a = 2;

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

tidb> create table t (a int primary key, b int, key (b)) partition by hash(a) (partition P0, partition p1, partition P2);
Query OK, 0 rows affected (0,01 sec)

tidb> insert into t values (1,1),(2,2),(3,3);
Query OK, 3 rows affected (0,00 sec)
Records: 3  Duplicates: 0  Warnings: 0

tidb> analyze table t;
Query OK, 0 rows affected, 3 warnings (0,03 sec)

tidb> set @@tidb_partition_prune_mode = 'static';
Query OK, 0 rows affected (0,00 sec)

tidb> explain select * from t where a IN (1,2);
+-------------------+---------+------+---------------+--------------------------------------------+
| id                | estRows | task | access object | operator info                              |
+-------------------+---------+------+---------------+--------------------------------------------+
| Batch_Point_Get_1 | 2.00    | root | table:t partition:p1,P2      | handle:[1 2], keep order:false, desc:false |
+-------------------+---------+------+---------------+--------------------------------------------+
1 row in set (0,00 sec)

tidb> explain select * from t where a = 1 OR a = 2;
+--------------------------+---------+------+---------------+--------------------------------------------+
| id                       | estRows | task | access object | operator info                              |
+--------------------------+---------+------+---------------+--------------------------------------------+
| PartitionUnion_9         | 2.00    | root |               |                                            |
| ├─Batch_Point_Get_10     | 1.00    | root | table:t partition:p1      | handle:[1 2], keep order:false, desc:false |
| └─Batch_Point_Get_11     | 1.00    | root | table:t partition:P2      | handle:[1 2], keep order:false, desc:false |
+--------------------------+---------+------+---------------+--------------------------------------------+
3 rows in set (0,00 sec)

tidb> set @@tidb_partition_prune_mode = 'dynamic';
Query OK, 0 rows affected (0,00 sec)

tidb> explain select * from t where a IN (1,2);
+-------------------+---------+------+---------------+--------------------------------------------+
| id                | estRows | task | access object | operator info                              |
+-------------------+---------+------+---------------+--------------------------------------------+
| Batch_Point_Get_1 | 2.00    | root | table:t partition:p1,P2      | handle:[1 2], keep order:false, desc:false |
+-------------------+---------+------+---------------+--------------------------------------------+
1 row in set (0,00 sec)

tidb> explain select * from t where a = 1 OR a = 2;
+------------------------+---------+-----------+-----------------+----------------------------------------------------+
| id                     | estRows | task      | access object   | operator info                                      |
+------------------------+---------+-----------+-----------------+----------------------------------------------------+
| TableReader_6          | 2.00    | root      | partition:p1,P2 | data:TableRangeScan_5                              |
| └─TableRangeScan_5     | 2.00    | cop[tikv] | table:t         | range:[1,1], [2,2], keep order:false, stats:pseudo |
+------------------------+---------+-----------+-----------------+----------------------------------------------------+
2 rows in set (0,00 sec)

3. What did you see instead (Required)

tidb> create table t (a int primary key, b int, key (b)) partition by hash(a) (partition P0, partition p1, partition P2);
Query OK, 0 rows affected (0,01 sec)

tidb> insert into t values (1,1),(2,2),(3,3);
Query OK, 3 rows affected (0,00 sec)
Records: 3  Duplicates: 0  Warnings: 0

tidb> analyze table t;
Query OK, 0 rows affected, 3 warnings (0,03 sec)

tidb> set @@tidb_partition_prune_mode = 'static';
Query OK, 0 rows affected (0,00 sec)

tidb> explain select * from t where a IN (1,2);
+-------------------+---------+------+---------------+--------------------------------------------+
| id                | estRows | task | access object | operator info                              |
+-------------------+---------+------+---------------+--------------------------------------------+
| Batch_Point_Get_1 | 2.00    | root | table:t       | handle:[1 2], keep order:false, desc:false |
+-------------------+---------+------+---------------+--------------------------------------------+
1 row in set (0,00 sec)

tidb> explain select * from t where a = 1 OR a = 2;
+--------------------------+---------+------+---------------+--------------------------------------------+
| id                       | estRows | task | access object | operator info                              |
+--------------------------+---------+------+---------------+--------------------------------------------+
| PartitionUnion_9         | 2.00    | root |               |                                            |
| ├─Batch_Point_Get_10     | 1.00    | root | table:t       | handle:[1 2], keep order:false, desc:false |
| └─Batch_Point_Get_11     | 1.00    | root | table:t       | handle:[1 2], keep order:false, desc:false |
+--------------------------+---------+------+---------------+--------------------------------------------+
3 rows in set (0,00 sec)

tidb> set @@tidb_partition_prune_mode = 'dynamic';
Query OK, 0 rows affected (0,00 sec)

tidb> explain select * from t where a IN (1,2);
+-------------------+---------+------+---------------+--------------------------------------------+
| id                | estRows | task | access object | operator info                              |
+-------------------+---------+------+---------------+--------------------------------------------+
| Batch_Point_Get_1 | 2.00    | root | table:t       | handle:[1 2], keep order:false, desc:false |
+-------------------+---------+------+---------------+--------------------------------------------+
1 row in set (0,00 sec)

tidb> explain select * from t where a = 1 OR a = 2;
+------------------------+---------+-----------+-----------------+----------------------------------------------------+
| id                     | estRows | task      | access object   | operator info                                      |
+------------------------+---------+-----------+-----------------+----------------------------------------------------+
| TableReader_6          | 2.00    | root      | partition:p1,P2 | data:TableRangeScan_5                              |
| └─TableRangeScan_5     | 2.00    | cop[tikv] | table:t         | range:[1,1], [2,2], keep order:false, stats:pseudo |
+------------------------+---------+-----------+-----------------+----------------------------------------------------+
2 rows in set (0,00 sec)

4. What is your TiDB version? (Required)

Release Version: v5.5.0-alpha-489-g493eb45c75
Edition: Community
Git Commit Hash: 493eb45c75a8f9687d5bf9185e5e167aadc81012
Git Branch: master
UTC Build Time: 2022-03-04 00:14:01
GoVersion: go1.17
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false