对两个整型列的查询花费的时间长得离谱

Question

我有一个(由Django生成的)查询，如下所示：

SELECT `geo_ip`.`id`, `geo_ip`.`start_ip`,
       `geo_ip`.`end_ip`, `geo_ip`.`start`,
       `geo_ip`.`end`, `geo_ip`.`cc`, `geo_ip`.`cn`
FROM `geo_ip`
WHERE (`geo_ip`.`start` <= 2084738290 AND `geo_ip`.`end` >= 2084738290 )
LIMIT 1

它查询一个包含134189个条目的GeoLocating表。当添加索引时，每个查询的执行时间都大于100ms，这使得它不能用于多个一次性的事情。我将缓存响应，这样我只需要查找一次IP，但我很好奇是否错过了一些明显的方法来使其速度更快。我的表格：

CREATE TABLE `geo_ip` (
  `start_ip` char(15) NOT NULL,
  `end_ip` char(15) NOT NULL,
  `start` bigint(20) NOT NULL,
  `end` bigint(20) NOT NULL,
  `cc` varchar(6) NOT NULL,
  `cn` varchar(150) NOT NULL,
  `id` int(11) NOT NULL AUTO_INCREMENT,
  PRIMARY KEY (`id`),
) ENGINE=InnoDB AUTO_INCREMENT=134190 DEFAULT CHARSET=latin1

在两列上创建索引，如下所示：

ALTER TABLE geo_ip ADD INDEX (start, end);

给出以下解释：

EXPLAIN SELECT geo_ip.id, geo_ip.start_ip, geo_ip.end_ip,
               geo_ip.start, geo_ip.end, geo_ip.cc, geo_ip.cn
FROM geo_ip
WHERE (geo_ip.end >= 2084738290 AND geo_ip.start < 2084738290)
LIMIT 1;
+----+-------------+--------+-------+---------------+-------+---------+------+-------+----------+-------------+
| id | select_type | table  | type  | possible_keys | key   | key_len | ref  | rows  | filtered | Extra       |
+----+-------------+--------+-------+---------------+-------+---------+------+-------+----------+-------------+
|  1 | SIMPLE      | geo_ip | range | start         | start | 8       | NULL | 67005 |   100.00 | Using where |
+----+-------------+--------+-------+---------------+-------+---------+------+-------+----------+-------------+

完成选择需要超过100ms的时间：

SELECT geo_ip.id, geo_ip.start_ip, geo_ip.end_ip,
       geo_ip.start, geo_ip.end, geo_ip.cc,
       geo_ip.cn
FROM geo_ip
WHERE (geo_ip.end >= 2084738290 and geo_ip.start < 2084738290)
LIMIT 1;
+-------+--------------+----------------+------------+------------+----+-----------+
| id    | start_ip     | end_ip         | start      | end        | cc | cn        |
+-------+--------------+----------------+------------+------------+----+-----------+
| 51725 | 124.66.128.0 | 124.66.159.255 | 2084732928 | 2084741119 | SG | Singapore |
+-------+--------------+----------------+------------+------------+----+-----------+
1 row in set (0.18 sec)

比拥有一个单独的索引更昂贵：

ALTER TABLE geo_ip ADD INDEX (`start`);
ALTER TABLE geo_ip ADD INDEX (`end`);
+----+-------------+--------+-------+---------------+-------+---------+------+-------+-------------+
| id | select_type | table  | type  | possible_keys | key   | key_len | ref  | rows  | Extra       |
+----+-------------+--------+-------+---------------+-------+---------+------+-------+-------------+
|  1 | SIMPLE      | geo_ip | range | start,end     | start | 8       | NULL | 68017 | Using where |
+----+-------------+--------+-------+---------------+-------+---------+------+-------+-------------+

完成这些请求大约需要100ms：

SELECT geo_ip.id, geo_ip.start_ip, geo_ip.end_ip, geo_ip.start, geo_ip.end, geo_ip.cc, geo_ip.cn FROM geo_ip
WHERE (geo_ip.end >= 2084738290 AND geo_ip.start < 2084738290) limit 1;
+-------+--------------+----------------+------------+------------+----+-----------+
| id    | start_ip     | end_ip         | start      | end        | cc | cn        |
+-------+--------------+----------------+------------+------------+----+-----------+
| 51725 | 124.66.128.0 | 124.66.159.255 | 2084732928 | 2084741119 | SG | Singapore |
+-------+--------------+----------------+------------+------------+----+-----------+
1 row in set (0.11 sec)

但是这两种方法都需要很长的时间，有没有可能解决这个问题呢？

Answer 1

时间总是消耗在"where“子句中。

由于您正在处理两个不同的字段，因此它必须读取大量索引才能找出您想要的记录。

我应该这样做我的表：

+-------+-------+----------------+------------+----+-----------+
| id    | type  | ip             | geo        | cc | cn        |
+-------+-------+----------------+------------+----+-----------+
| 51725 | start | 124.66.159.255 | 2084732928 | SG | Singapore |
+-------+-------+----------------+------------+----+-----------+
| 51726 | end   | 124.66.159.255 | 2084732928 | SG | Singapore |
+-------+-------+----------------+------------+----+-----------+

这样我就可以选择这个：

select * from table where geo between '2084732927' and '2084732928'

在地理位置上有一个索引。应该会快很多很多。但是很抱歉，我没有时间去尝试。