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GeoLocating表,其中包含134189个条目。添加索引时,每个查询都需要> 100毫秒才能执行,这使得它不能用于多个一次性事务。我要缓存响应,所以我只需要进行一次IP查找,但我很好奇,如果我错过了一些明显的方法,使它更快。我的表:
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100毫秒:
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)
比单个索引更昂贵:
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100毫秒:
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)
但这两种方法都花了太长时间,是否有可能对此采取任何措施?
答案 0 :(得分:0)
“where”子句总是消耗时间。
因为您正在使用“低于”或“大于”的两个不同字段,所以必须读取大量索引以找出您想要的记录。
我应该这样做我的桌子:
+-------+-------+----------------+------------+----+-----------+
| 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:
select * from table where geo between '2084732927' and '2084732928'
带有geo索引。 应该更快,更快。但对不起,我没时间尝试。