remove invalid predicates after partition pruning

[XuHuaiyu]

Development Task

table schema:

CREATE TABLE `t` (
  `a` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin
PARTITION BY RANGE ( `a` ) (
  PARTITION `p0` VALUES LESS THAN (1),
  PARTITION `p1` VALUES LESS THAN (2),
  PARTITION `p2` VALUES LESS THAN (3),
  PARTITION `p_max` VALUES LESS THAN (MAXVALUE)
)

query:

desc select * from t where a = 1;
+-------------------------+----------+-----------+-----------------------+--------------------------------+
| id                      | estRows  | task      | access object         | operator info                  |
+-------------------------+----------+-----------+-----------------------+--------------------------------+
| TableReader_9           | 10.00    | root      |                       | data:Selection_8               |
| └─Selection_8           | 10.00    | cop[tikv] |                       | eq(test.t.a, 1)                |
|   └─TableFullScan_7     | 10000.00 | cop[tikv] | table:t, partition:p1 | keep order:false, stats:pseudo |
+-------------------------+----------+-----------+-----------------------+--------------------------------+
3 rows in set (0.00 sec)

Actually, we can remove the a=1 after partition pruning for this case.

[zhuo-zhi]

/assign