create table ten(a int);

insert into ten values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);

create table one_k(a int);

insert into one_k select A.a + B.a* 10 + C.a * 100 from ten A, ten B, ten C;

create table t1 (lb int, rb int);

insert into t1 values (1,2);

insert into t1 values (3,5);

insert into t1 values (10, 20);

create table t2 (key1 int, col1 int, key(key1));

insert into t2 select a,a from ten;

insert into t2 select 15,15 from one_k;

explain select * from t1, t2 where t2.key1 between t1.lb and t1.rb;

+------+-------------+-------+------+---------------+------+---------+------+------+------------------------------------------------+

| id   | select_type | table | type | possible_keys | key  | key_len | ref  | rows | Extra                                          |

+------+-------------+-------+------+---------------+------+---------+------+------+------------------------------------------------+

|    1 | SIMPLE      | t1    | ALL  | NULL          | NULL | NULL    | NULL |    3 |                                                |

|    1 | SIMPLE      | t2    | ALL  | key1          | NULL | NULL    | NULL | 1010 | Range checked for each record (index map: 0x1) |

+------+-------------+-------+------+---------------+------+---------+------+------+------------------------------------------------+

MariaDB [test]> analyze select * from t1, t2 where t2.key1 between t1.lb and t1.rb;

+------+-------------+-------+------+---------------+------+---------+------+------+--------+----------+------------+------------------------------------------------+

| id   | select_type | table | type | possible_keys | key  | key_len | ref  | rows | r_rows | filtered | r_filtered | Extra                                          |

+------+-------------+-------+------+---------------+------+---------+------+------+--------+----------+------------+------------------------------------------------+

|    1 | SIMPLE      | t1    | ALL  | NULL          | NULL | NULL    | NULL |    3 |   3.00 |   100.00 |     100.00 |                                                |

|    1 | SIMPLE      | t2    | ALL  | key1          | NULL | NULL    | NULL | 1010 | 338.33 |   100.00 |      99.01 | Range checked for each record (index map: 0x1) |

+------+-------------+-------+------+---------------+------+---------+------+------+--------+----------+------------+------------------------------------------------+

MariaDB [test]> analyze format=json select * from t1, t2 where t2.key1 between t1.lb and t1.rb\G

*************************** 1. row ***************************                                                                                              

EXPLAIN: {                                                                                                                                                  

  "query_block": {                                                                                                                                          

    "select_id": 1,                                                                                                                                         

    "r_loops": 1,                                                                                                                                           

    "r_total_time_ms": 32.893,                                                                                                                              

    "table": {                                                                                                                                              

      "table_name": "t1",                                                                                                                                   

      "access_type": "ALL",                                                                                                                                 

      "r_loops": 1,                                                                                                                                         

      "rows": 3,                                                                                                                                            

      "r_rows": 3,                                                                                                                                          

      "r_total_time_ms": 0.1226,

      "filtered": 100,

      "r_filtered": 100

    },

    "range-checked-for-each-record": {

      "keys": ["key1"],

      "table": {

        "table_name": "t2",

        "access_type": "ALL",

        "possible_keys": ["key1"],

        "r_loops": 3,

        "rows": 1010,

        "r_rows": 338.33,

        "r_total_time_ms": 16.334,

        "filtered": 100,

        "r_filtered": 99.015

      }

    }

  }

}