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Asked: 2026-05-14T14:09:23+00:00

I have two tables, Table A with 700,000 entries and Table B with 600,000

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I have two tables, Table A with 700,000 entries and Table B with 600,000 entries. The structure is as follows:

Table A:

+-----------+---------------------+------+-----+---------+----------------+
| Field     | Type                | Null | Key | Default | Extra          |
+-----------+---------------------+------+-----+---------+----------------+
| id        | bigint(20) unsigned | NO   | PRI | NULL    | auto_increment | 
| number    | bigint(20) unsigned | YES  |     | NULL    |                | 
+-----------+---------------------+------+-----+---------+----------------+

Table B:

+-------------+---------------------+------+-----+---------+----------------+
| Field       | Type                | Null | Key | Default | Extra          |
+-------------+---------------------+------+-----+---------+----------------+
| id          | bigint(20) unsigned | NO   | PRI | NULL    | auto_increment | 
| number_s    | bigint(20) unsigned | YES  | MUL | NULL    |                | 
| number_e    | bigint(20) unsigned | YES  | MUL | NULL    |                | 
| source      | varchar(50)         | YES  |     | NULL    |                |
+-------------+---------------------+------+-----+---------+----------------+

I am trying to find if any of the values in Table A are present in Table B using the following code:

$sql = "SELECT number from TableA";
$result = mysql_query($sql) or die(mysql_error());

while($row = mysql_fetch_assoc($result)) {
        $number = $row['number'];
        $sql = "SELECT source, count(source) FROM TableB WHERE number_s < $number AND number_e > $number GROUP BY source";
        $re = mysql_query($sql) or die(mysql_error);
        while($ro = mysql_fetch_array($re)) {
                echo $number."\t".$ro[0]."\t".$ro[1]."\n";
        }
}

I was hoping that the query would go fast but then for some reason, it isn’t terrible fast. My explain on the select (with a particular value of “number”) gives me the following:

mysql> explain SELECT source, count(source) FROM TableB WHERE number_s < 1812194440 AND number_e > 1812194440 GROUP BY source;
+----+-------------+------------+------+-------------------------+------+---------+------+--------+----------------------------------------------+
| id | select_type | table      | type | possible_keys           | key  | key_len | ref  | rows   | Extra                                        |
+----+-------------+------------+------+-------------------------+------+---------+------+--------+----------------------------------------------+
|  1 | SIMPLE      | TableB     | ALL  | number_s,number_e       | NULL | NULL    | NULL | 696325 | Using where; Using temporary; Using filesort | 
+----+-------------+------------+------+-------------------------+------+---------+------+--------+----------------------------------------------+
1 row in set (0.00 sec)

Is there any optimization that I can squeeze out of this?

I tried writing a stored procedure for the same task but it doesn’t even seem to work in the first place… It doesn’t give any syntax errors… I tried running it for a day and it was still running which felt odd.

CREATE PROCEDURE Filter() 
Begin 
  DECLARE number BIGINT UNSIGNED; 
  DECLARE x INT; 
  DECLARE done INT DEFAULT 0; 
  DECLARE cur1 CURSOR FOR SELECT number FROM TableA; 
  DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1; 
  CREATE TEMPORARY TABLE IF NOT EXISTS Flags(number bigint unsigned, count int(11)); 
  OPEN cur1; 
  hist_loop: LOOP 
    FETCH cur1 INTO number; 
    SELECT count(*) from TableB WHERE number_s < number AND number_e > number INTO x; 
    IF done = 1 THEN 
      LEAVE hist_loop; 
    END IF; 
    IF x IS NOT NULL AND x>0 THEN 
      INSERT INTO Flags(number, count) VALUES(number, x); 
    END IF; 
  END LOOP hist_loop; 
  CLOSE cur1;
END
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1 Answer

  1. Editorial Team

    You are trying to find intervals which contain a point. This is not so fast with a B-tree index (the default index type in most databases), however an R-tree index will work well for this sort of query. MySQL doesn’t allow you to change the type of an index directly, but you can force MySQL to use an R-Tree by using the GEOMETRY column type.

    Quassnoi covers this in his article on nested sets in MySQL. While it’s not quite the same, it’s very similar. A quote from the article:

    There is also a certain class of tasks
    that require searching for all ranges
    containing a known value:

    * Searching for an IP address in the IP range ban list
* Searching for a given date within a date range

    and several others. These tasks can be
    improved by using R-Tree capabilities
    of MySQL

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