mysql: [Warning] Using a password on the command line interface can be insecure.
+---------------+
| mysql_version |
+---------------+
| 9.7.1         |
+---------------+
+-----------------------+-------+
| Variable_name         | Value |
+-----------------------+-------+
| optimizer_prune_level | 0     |
+-----------------------+-------+
+-----------------------------+---------+----------+----------+
| Table                       | Op      | Msg_type | Msg_text |
+-----------------------------+---------+----------+----------+
| mysql_null_eq_impossible.t0 | analyze | status   | OK       |
| mysql_null_eq_impossible.t1 | analyze | status   | OK       |
+-----------------------------+---------+----------+----------+
+---------+------------+
| t0_rows | t0_null_c0 |
+---------+------------+
|   52000 |       2000 |
+---------+------------+
+---------+------------+
| t1_rows | t1_null_c0 |
+---------+------------+
|   52000 |       2000 |
+---------+------------+
+------------------------+
| eq_join_should_be_zero |
+------------------------+
|                      0 |
+------------------------+
+-------------------------+
| null_safe_join_has_rows |
+-------------------------+
|                       1 |
+-------------------------+
+-----------------------+-------+
| Variable_name         | Value |
+-----------------------+-------+
| optimizer_prune_level | 0     |
+-----------------------+-------+
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| EXPLAIN                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| {
  "query": "/* select#1 */ select `mysql_null_eq_impossible`.`t1`.`c1` AS `ref0`,`mysql_null_eq_impossible`.`t0`.`c0` AS `c0` from `mysql_null_eq_impossible`.`t1` join `mysql_null_eq_impossible`.`t0` where ((`mysql_null_eq_impossible`.`t1`.`c0` = `mysql_null_eq_impossible`.`t0`.`c0`) and (`mysql_null_eq_impossible`.`t0`.`c0` is null)) order by `mysql_null_eq_impossible`.`t0`.`c3`,`mysql_null_eq_impossible`.`t0`.`c0` desc limit 2",
  "query_plan": {
    "limit": 2,
    "inputs": [
      {
        "inputs": [
          {
            "inputs": [
              {
                "covering": false,
                "operation": "Index lookup on t0 using i0 (c0 = NULL), with index condition: (t0.c0 is null)",
                "index_name": "i0",
                "table_name": "t0",
                "access_type": "index",
                "key_columns": [
                  "c0"
                ],
                "schema_name": "mysql_null_eq_impossible",
                "used_columns": [
                  "c0",
                  "c3"
                ],
                "estimated_rows": 2000.0,
                "lookup_condition": "c0 = NULL",
                "index_access_type": "index_lookup",
                "lookup_references": [
                  "const"
                ],
                "estimated_total_cost": 416.75,
                "pushed_index_condition": "(t0.c0 is null)"
              }
            ],
            "operation": "Sort: t0.c3, t0.c0 DESC",
            "access_type": "sort",
            "sort_fields": [
              "t0.c3",
              "t0.c0 DESC"
            ],
            "estimated_rows": 2000.0,
            "estimated_total_cost": 416.75
          },
          {
            "inputs": [
              {
                "covering": true,
                "operation": "Covering index lookup on t1 using i3 (c0 = NULL)",
                "index_name": "i3",
                "table_name": "t1",
                "access_type": "index",
                "key_columns": [
                  "c0"
                ],
                "schema_name": "mysql_null_eq_impossible",
                "used_columns": [
                  "c0",
                  "c1"
                ],
                "estimated_rows": 2000.0,
                "lookup_condition": "c0 = NULL",
                "index_access_type": "index_lookup",
                "lookup_references": [
                  "const"
                ],
                "estimated_total_cost": 6.945029239766082
              }
            ],
            "condition": "(t1.c0 = t0.c0)",
            "operation": "Filter: (t1.c0 = t0.c0)",
            "access_type": "filter",
            "estimated_rows": 2000.0,
            "filter_columns": [
              "mysql_null_eq_impossible.t0.c0",
              "mysql_null_eq_impossible.t1.c0"
            ],
            "estimated_total_cost": 6.945029239766082
          }
        ],
        "join_type": "inner join",
        "operation": "Nested loop inner join",
        "access_type": "join",
        "estimated_rows": 4000000.0,
        "join_algorithm": "nested_loop",
        "estimated_total_cost": 414106.8084795322
      }
    ],
    "operation": "Limit: 2 row(s)",
    "access_type": "limit",
    "limit_offset": 0,
    "estimated_rows": 2.0,
    "estimated_total_cost": 414106.8084795322
  },
  "query_type": "select",
  "json_schema_version": "2.0"
} |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| EXPLAIN                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| -> Limit: 2 row(s)  (cost=414107 rows=2) (actual time=1870..1870 rows=0 loops=1)
    -> Nested loop inner join  (cost=414107 rows=4e+6) (actual time=1870..1870 rows=0 loops=1)
        -> Sort: t0.c3, t0.c0 DESC  (cost=417 rows=2000) (actual time=3.56..3.82 rows=2000 loops=1)
            -> Index lookup on t0 using i0 (c0 = NULL), with index condition: (t0.c0 is null)  (cost=417 rows=2000) (actual time=0.0116..3.04 rows=2000 loops=1)
        -> Filter: (t1.c0 = t0.c0)  (cost=6.95 rows=2000) (actual time=0.933..0.933 rows=0 loops=2000)
            -> Covering index lookup on t1 using i3 (c0 = NULL)  (cost=6.95 rows=2000) (actual time=0.00163..0.842 rows=2000 loops=2000)
 |
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| EXPLAIN                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| {
  "query": "/* select#1 */ select /*+ JOIN_ORDER(@`select#1` `t1`,`t0`) */ `mysql_null_eq_impossible`.`t1`.`c1` AS `ref0`,`mysql_null_eq_impossible`.`t0`.`c0` AS `c0` from `mysql_null_eq_impossible`.`t1` join `mysql_null_eq_impossible`.`t0` where ((`mysql_null_eq_impossible`.`t0`.`c0` = `mysql_null_eq_impossible`.`t1`.`c0`) and (`mysql_null_eq_impossible`.`t1`.`c0` is null)) order by `mysql_null_eq_impossible`.`t0`.`c3`,`mysql_null_eq_impossible`.`t0`.`c0` desc limit 2",
  "query_plan": {
    "limit": 2,
    "inputs": [
      {
        "inputs": [
          {
            "inputs": [
              {
                "inputs": [
                  {
                    "inputs": [
                      {
                        "covering": true,
                        "operation": "Covering index lookup on t1 using i3 (c0 = NULL)",
                        "index_name": "i3",
                        "table_name": "t1",
                        "access_type": "index",
                        "key_columns": [
                          "c0"
                        ],
                        "schema_name": "mysql_null_eq_impossible",
                        "used_columns": [
                          "c0",
                          "c1"
                        ],
                        "estimated_rows": 2000.0,
                        "lookup_condition": "c0 = NULL",
                        "index_access_type": "index_lookup",
                        "lookup_references": [
                          "const"
                        ],
                        "estimated_total_cost": 206.8450292397661
                      }
                    ],
                    "condition": "(t1.c0 is null)",
                    "operation": "Filter: (t1.c0 is null)",
                    "access_type": "filter",
                    "estimated_rows": 2000.0,
                    "filter_columns": [
                      "mysql_null_eq_impossible.t1.c0"
                    ],
                    "estimated_total_cost": 206.8450292397661
                  },
                  {
                    "covering": false,
                    "operation": "Index lookup on t0 using i0 (c0 = NULL), with index condition: (t0.c0 = t1.c0)",
                    "index_name": "i0",
                    "table_name": "t0",
                    "access_type": "index",
                    "key_columns": [
                      "c0"
                    ],
                    "schema_name": "mysql_null_eq_impossible",
                    "used_columns": [
                      "c0",
                      "c3"
                    ],
                    "estimated_rows": 2000.0,
                    "lookup_condition": "c0 = NULL",
                    "index_access_type": "index_lookup",
                    "lookup_references": [
                      "const"
                    ],
                    "estimated_total_cost": 216.85,
                    "pushed_index_condition": "(t0.c0 = t1.c0)"
                  }
                ],
                "join_type": "inner join",
                "operation": "Nested loop inner join",
                "access_type": "join",
                "estimated_rows": 4000000.0,
                "join_algorithm": "nested_loop",
                "estimated_total_cost": 833706.8450292398
              }
            ],
            "operation": "Stream results",
            "access_type": "stream",
            "estimated_rows": 4000000.0,
            "estimated_total_cost": 833706.8450292398
          }
        ],
        "operation": "Sort: t0.c3, t0.c0 DESC, limit input to 2 row(s) per chunk",
        "access_type": "sort",
        "sort_fields": [
          "t0.c3",
          "t0.c0 DESC"
        ],
        "per_chunk_limit": 2
      }
    ],
    "operation": "Limit: 2 row(s)",
    "access_type": "limit",
    "limit_offset": 0
  },
  "query_type": "select",
  "json_schema_version": "2.0"
} |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| EXPLAIN                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| -> Limit: 2 row(s)  (actual time=321..321 rows=0 loops=1)
    -> Sort: t0.c3, t0.c0 DESC, limit input to 2 row(s) per chunk  (actual time=321..321 rows=0 loops=1)
        -> Stream results  (cost=833707 rows=4e+6) (actual time=321..321 rows=0 loops=1)
            -> Nested loop inner join  (cost=833707 rows=4e+6) (actual time=321..321 rows=0 loops=1)
                -> Filter: (t1.c0 is null)  (cost=207 rows=2000) (actual time=0.00731..1.4 rows=2000 loops=1)
                    -> Covering index lookup on t1 using i3 (c0 = NULL)  (cost=207 rows=2000) (actual time=0.00643..1.2 rows=2000 loops=1)
                -> Index lookup on t0 using i0 (c0 = NULL), with index condition: (t0.c0 = t1.c0)  (cost=217 rows=2000) (actual time=0.159..0.159 rows=0 loops=2000)
 |
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| EXPLAIN                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| {
  "query": "/* select#1 */ select `mysql_null_eq_impossible`.`t1`.`c1` AS `ref0`,`mysql_null_eq_impossible`.`t0`.`c0` AS `c0` from `mysql_null_eq_impossible`.`t1` join `mysql_null_eq_impossible`.`t0` where ((`mysql_null_eq_impossible`.`t0`.`c0` = `mysql_null_eq_impossible`.`t1`.`c0`) and (`mysql_null_eq_impossible`.`t1`.`c0` is null))",
  "query_plan": {
    "inputs": [
      {
        "inputs": [
          {
            "covering": true,
            "operation": "Covering index lookup on t1 using i3 (c0 = NULL)",
            "index_name": "i3",
            "table_name": "t1",
            "access_type": "index",
            "key_columns": [
              "c0"
            ],
            "schema_name": "mysql_null_eq_impossible",
            "used_columns": [
              "c0",
              "c1"
            ],
            "estimated_rows": 2000.0,
            "lookup_condition": "c0 = NULL",
            "index_access_type": "index_lookup",
            "lookup_references": [
              "const"
            ],
            "estimated_total_cost": 206.8450292397661
          }
        ],
        "condition": "(t1.c0 is null)",
        "operation": "Filter: (t1.c0 is null)",
        "access_type": "filter",
        "estimated_rows": 2000.0,
        "filter_columns": [
          "mysql_null_eq_impossible.t1.c0"
        ],
        "estimated_total_cost": 206.8450292397661
      },
      {
        "inputs": [
          {
            "covering": true,
            "operation": "Covering index lookup on t0 using i0 (c0 = NULL)",
            "index_name": "i0",
            "table_name": "t0",
            "access_type": "index",
            "key_columns": [
              "c0"
            ],
            "schema_name": "mysql_null_eq_impossible",
            "used_columns": [
              "c0"
            ],
            "estimated_rows": 2000.0,
            "lookup_condition": "c0 = NULL",
            "index_access_type": "index_lookup",
            "lookup_references": [
              "const"
            ],
            "estimated_total_cost": 4.700773449585151
          }
        ],
        "condition": "(t0.c0 = t1.c0)",
        "operation": "Filter: (t0.c0 = t1.c0)",
        "access_type": "filter",
        "estimated_rows": 2000.0,
        "filter_columns": [
          "mysql_null_eq_impossible.t0.c0",
          "mysql_null_eq_impossible.t1.c0"
        ],
        "estimated_total_cost": 4.700773449585151
      }
    ],
    "join_type": "inner join",
    "operation": "Nested loop inner join",
    "access_type": "join",
    "estimated_rows": 4000000.0,
    "join_algorithm": "nested_loop",
    "estimated_total_cost": 409408.39192841004
  },
  "query_type": "select",
  "json_schema_version": "2.0"
} |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| EXPLAIN                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| -> Nested loop inner join  (cost=409408 rows=4e+6) (actual time=1710..1710 rows=0 loops=1)
    -> Filter: (t1.c0 is null)  (cost=207 rows=2000) (actual time=0.00742..1.32 rows=2000 loops=1)
        -> Covering index lookup on t1 using i3 (c0 = NULL)  (cost=207 rows=2000) (actual time=0.00659..1.13 rows=2000 loops=1)
    -> Filter: (t0.c0 = t1.c0)  (cost=4.7 rows=2000) (actual time=0.854..0.854 rows=0 loops=2000)
        -> Covering index lookup on t0 using i0 (c0 = NULL)  (cost=4.7 rows=2000) (actual time=0.00159..0.761 rows=2000 loops=2000)
 |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+-----------------------+-------+
| Variable_name         | Value |
+-----------------------+-------+
| optimizer_prune_level | 1     |
+-----------------------+-------+
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| EXPLAIN                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| {
  "query": "/* select#1 */ select `mysql_null_eq_impossible`.`t1`.`c1` AS `ref0`,`mysql_null_eq_impossible`.`t0`.`c0` AS `c0` from `mysql_null_eq_impossible`.`t1` join `mysql_null_eq_impossible`.`t0` where ((`mysql_null_eq_impossible`.`t1`.`c0` = `mysql_null_eq_impossible`.`t0`.`c0`) and (`mysql_null_eq_impossible`.`t0`.`c0` is null)) order by `mysql_null_eq_impossible`.`t0`.`c3`,`mysql_null_eq_impossible`.`t0`.`c0` desc limit 2",
  "query_plan": {
    "limit": 2,
    "inputs": [
      {
        "inputs": [
          {
            "inputs": [
              {
                "covering": false,
                "operation": "Index lookup on t0 using i0 (c0 = NULL), with index condition: (t0.c0 is null)",
                "index_name": "i0",
                "table_name": "t0",
                "access_type": "index",
                "key_columns": [
                  "c0"
                ],
                "schema_name": "mysql_null_eq_impossible",
                "used_columns": [
                  "c0",
                  "c3"
                ],
                "estimated_rows": 2000.0,
                "lookup_condition": "c0 = NULL",
                "index_access_type": "index_lookup",
                "lookup_references": [
                  "const"
                ],
                "estimated_total_cost": 416.75,
                "pushed_index_condition": "(t0.c0 is null)"
              }
            ],
            "operation": "Sort: t0.c3, t0.c0 DESC",
            "access_type": "sort",
            "sort_fields": [
              "t0.c3",
              "t0.c0 DESC"
            ],
            "estimated_rows": 2000.0,
            "estimated_total_cost": 416.75
          },
          {
            "inputs": [
              {
                "covering": true,
                "operation": "Covering index lookup on t1 using i3 (c0 = NULL)",
                "index_name": "i3",
                "table_name": "t1",
                "access_type": "index",
                "key_columns": [
                  "c0"
                ],
                "schema_name": "mysql_null_eq_impossible",
                "used_columns": [
                  "c0",
                  "c1"
                ],
                "estimated_rows": 2000.0,
                "lookup_condition": "c0 = NULL",
                "index_access_type": "index_lookup",
                "lookup_references": [
                  "const"
                ],
                "estimated_total_cost": 6.945029239766082
              }
            ],
            "condition": "(t1.c0 = t0.c0)",
            "operation": "Filter: (t1.c0 = t0.c0)",
            "access_type": "filter",
            "estimated_rows": 2000.0,
            "filter_columns": [
              "mysql_null_eq_impossible.t0.c0",
              "mysql_null_eq_impossible.t1.c0"
            ],
            "estimated_total_cost": 6.945029239766082
          }
        ],
        "join_type": "inner join",
        "operation": "Nested loop inner join",
        "access_type": "join",
        "estimated_rows": 4000000.0,
        "join_algorithm": "nested_loop",
        "estimated_total_cost": 414106.8084795322
      }
    ],
    "operation": "Limit: 2 row(s)",
    "access_type": "limit",
    "limit_offset": 0,
    "estimated_rows": 2.0,
    "estimated_total_cost": 414106.8084795322
  },
  "query_type": "select",
  "json_schema_version": "2.0"
} |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| EXPLAIN                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| -> Limit: 2 row(s)  (cost=414107 rows=2) (actual time=1872..1872 rows=0 loops=1)
    -> Nested loop inner join  (cost=414107 rows=4e+6) (actual time=1872..1872 rows=0 loops=1)
        -> Sort: t0.c3, t0.c0 DESC  (cost=417 rows=2000) (actual time=3.37..3.63 rows=2000 loops=1)
            -> Index lookup on t0 using i0 (c0 = NULL), with index condition: (t0.c0 is null)  (cost=417 rows=2000) (actual time=0.0114..2.81 rows=2000 loops=1)
        -> Filter: (t1.c0 = t0.c0)  (cost=6.95 rows=2000) (actual time=0.934..0.934 rows=0 loops=2000)
            -> Covering index lookup on t1 using i3 (c0 = NULL)  (cost=6.95 rows=2000) (actual time=0.00164..0.844 rows=2000 loops=2000)
 |
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
