constant propagation does not work

[XuHuaiyu]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. What did you do?

CREATE TABLE `t` (
  `a` int(11) DEFAULT NULL,
  `b` int(11) DEFAULT NULL,
  `c` int(11) DEFAULT NULL
);
desc select * from t where a = 1 and a = 2;

2. What did you expect to see?

tidb> desc select * from t where a = 1 and a = 2;

TableDual

3. What did you see instead?

tidb> desc select * from t where a = 1 and a = 2;
+---------------------+----------+-----------+------------------------------------------------------------+
| id                  | count    | task      | operator info                                              |
+---------------------+----------+-----------+------------------------------------------------------------+
| TableReader_7       | 0.00     | root      | data:Selection_6                                           |
| └─Selection_6       | 0.00     | cop[tikv] | eq(amldb.t.a, 1), eq(amldb.t.a, 2)                         |
|   └─TableScan_5     | 10000.00 | cop[tikv] | table:t, range:[-inf,+inf], keep order:false, stats:pseudo |
+---------------------+----------+-----------+------------------------------------------------------------+
3 rows in set (0.00 sec)

4. What version of TiDB are you using (tidb-server -V or run select tidb_version(); on TiDB)?

tidb> select tidb_version();
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tidb_version()                                                                                                                                                                                                                                                                                        |
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Release Version: v4.0.0-alpha-1334-g07e642c92
Git Commit Hash: 07e642c9230ccb7c1537b27442f1fe8433e65f8a
Git Branch: master
UTC Build Time: 2020-01-15 06:52:57
GoVersion: go1.13
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false |
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

[ou-bing]

/pick-up

[ti-challenge-bot]

It is not a pickable issue!

Details

Tip : If you want this issue to be picked, you need to add a challenge-program label to it.

Warning: None

[XuHuaiyu]

fixed by #21061

[ti-srebot]

Please edit this comment or add a new 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) (optional)

2. Symptom (optional)

3. All Trigger Conditions (optional)

4. Workaround (optional)

5. Affected versions

6. Fixed versions