标签：mysql range-types index datatypes
确定IP是否包含在CIDR块中的最快方法是什么？
目前,每当我存储一个CIDR地址时,我还会创建两列来启动和结束IP地址.开始和结束IP地址被索引.如果我想查看哪个网络包含一个地址,那么我查看start_ip和end_ip之间的ip,这看起来不太理想.
它发生在我身上我可以存储正确的移位号码,并且可以匹配类似移位的IP地址(在@cidr的情况下为660510)…
select @cidr, inet_aton(substring_index(@cidr,'/',1))>>(32-substring_index(@cidr,'/',-1));
+---------------+-----------------------------------------------------------------------------+
| @cidr | inet_aton(substring_index(@cidr,'/',1))>>(32-substring_index(@cidr,'/',-1)) |
+---------------+-----------------------------------------------------------------------------+
| 10.20.30.0/24 | 660510 |
+---------------+-----------------------------------------------------------------------------+
1 row in set (0.00 sec)
set @ip:='10.20.30.40';
Query OK, 0 rows affected (0.00 sec)
select @ip, inet_aton(@ip)>>(32-substring_index(@cidr,'/',-1));
+-------------+----------------------------------------------------+
| @ip | inet_aton(@ip)>>(32-substring_index(@cidr,'/',-1)) |
+-------------+----------------------------------------------------+
| 10.20.30.40 | 660510 |
+-------------+----------------------------------------------------+
1 row in set (0.00 sec)
为了以索引方式从中受益,我需要知道子网掩码(要移位的位数).否则,我将系统地比较位移(即,为每个可能的网络掩码(从0到24位)盲目移位).
我有其他优化来源,但优化在http://lite.ip2location.com/database/ip-asn发现的IP2Location™LITE IP-ASN数据库将是一个概念证明.
桌子…
CREATE TABLE `ip2loc_asn` (
`asn` bigint(20) DEFAULT NULL,
`cidr` varchar(50) DEFAULT NULL,
`start_ip` bigint(20) DEFAULT NULL,
`end_ip` bigint(20) DEFAULT NULL,
`name` varchar(250) DEFAULT NULL,
KEY `ip2locasn_startip_endip` (`start_ip`,`end_ip`),
KEY `asn` (`asn`),
KEY `cidr` (`cidr`)
) ENGINE=MyISAM; -- table is recreated monthly, MyISAM is the perfect engine
样本数据…
select * from ip2loc_asn limit 10;
+-------+--------------+----------+----------+-------------------------------+
| asn | cidr | start_ip | end_ip | name |
+-------+--------------+----------+----------+-------------------------------+
| 56203 | 1.0.4.0/24 | 16778240 | 16778495 | Big Red Group |
| 56203 | 1.0.5.0/24 | 16778496 | 16778751 | Big Red Group |
| 56203 | 1.0.6.0/24 | 16778752 | 16779007 | Big Red Group |
| 38803 | 1.0.7.0/24 | 16779008 | 16779263 | Goldenit Pty ltd Australia, A |
| 18144 | 1.0.64.0/18 | 16793600 | 16809983 | Energia Communications,Inc. |
| 9737 | 1.0.128.0/17 | 16809984 | 16842751 | TOT Public Company Limited |
| 9737 | 1.0.128.0/18 | 16809984 | 16826367 | TOT Public Company Limited |
| 9737 | 1.0.128.0/19 | 16809984 | 16818175 | TOT Public Company Limited |
| 23969 | 1.0.128.0/24 | 16809984 | 16810239 | TOT Public Company Limited |
| 23969 | 1.0.129.0/24 | 16810240 | 16810495 | TOT Public Company Limited |
+-------+--------------+----------+----------+-------------------------------+
10 rows in set (0.00 sec)
网络掩码范围从8到32位……
select min(substring_index(cidr,'/',-1)+0), max(substring_index(cidr,'/',-1)+0) from ip2loc_asn;
+-------------------------------------+-------------------------------------+
| min(substring_index(cidr,'/',-1)+0) | max(substring_index(cidr,'/',-1)+0) |
+-------------------------------------+-------------------------------------+
| 8 | 32 |
+-------------------------------------+-------------------------------------+
1 row in set (0.33 sec)
select * from ip2loc_asn where cidr like '%/8' limit 1;
+------+-----------+----------+----------+------------------------------+
| asn | cidr | start_ip | end_ip | name |
+------+-----------+----------+----------+------------------------------+
| 3356 | 4.0.0.0/8 | 67108864 | 83886079 | Level 3 Communications, Inc. |
+------+-----------+----------+----------+------------------------------+
1 row in set (0.00 sec)
select * from ip2loc_asn where cidr like '%/32' limit 1;
+-------+---------------+-----------+-----------+------+
| asn | cidr | start_ip | end_ip | name |
+-------+---------------+-----------+-----------+------+
| 51964 | 57.72.27.1/32 | 961026817 | 961026817 | |
+-------+---------------+-----------+-----------+------+
1 row in set (0.02 sec)
目前的执行计划……
explain select * from ip2loc_asn where inet_aton('10.20.30.40') between start_ip and end_ip;
+----+-------------+------------+-------+--------------------------+--------------------------+---------+------+-------+-----------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+------------+-------+--------------------------+--------------------------+---------+------+-------+-----------------------+
| 1 | SIMPLE | ip2loc_asn | range | ip2loc_asn_startip_endip | ip2loc_asn_startip_endip | 9 | NULL | 10006 | Using index condition |
+----+-------------+------------+-------+--------------------------+--------------------------+---------+------+-------+-----------------------+
1 row in set (0.00 sec)
我的笨拙尝试……
mysql to3_reference> alter table ip2loc_asn add column shifted_netmask int(10) unsigned;
Query OK, 626695 rows affected (4.06 sec)
Records: 626695 Duplicates: 0 Warnings: 0
mysql to3_reference> update ip2loc_asn set shifted_netmask = start_ip>>(32-substring_index(cidr,'/',-1));
Query OK, 626695 rows affected (5.98 sec)
Rows matched: 626695 Changed: 626695 Warnings: 0
mysql to3_reference> alter table ip2loc_asn add key ip2loc_asn_shiftednetmask (shifted_netmask);
Query OK, 626695 rows affected (5.83 sec)
Records: 626695 Duplicates: 0 Warnings: 0
旧方式：
select * from ip2loc_asn where inet_aton('8.8.8.0') between start_ip and end_ip;
+-------+------------+-----------------+--------------+-----------+-----------+------------------------------+
| asn | cidr | shifted_netmask | netmask_bits | start_ip | end_ip | name |
+-------+------------+-----------------+--------------+-----------+-----------+------------------------------+
| 3356 | 8.0.0.0/9 | 16 | 9 | 134217728 | 142606335 | Level 3 Communications, Inc. |
| 3356 | 8.0.0.0/8 | 8 | 8 | 134217728 | 150994943 | Level 3 Communications, Inc. |
| 15169 | 8.8.8.0/24 | 526344 | 24 | 134744064 | 134744319 | Google Inc. |
+-------+------------+-----------------+--------------+-----------+-----------+- -----------------------------+
3 rows in set (0.00 sec)
使用shifted_netmask的方法(不合需要 – 我正在进行全表扫描以发现网络掩码中的位数)…
select * from ip2loc_asn where shifted_netmask = inet_aton('8.8.8.0')>>32-netmask_bits;
+-------+------------+-----------------+--------------+-----------+-----------+------------------------------+
| asn | cidr | shifted_netmask | netmask_bits | start_ip | end_ip | name |
+-------+------------+-----------------+--------------+-----------+-----------+------------------------------+
| 3356 | 8.0.0.0/8 | 8 | 8 | 134217728 | 150994943 | Level 3 Communications, Inc. |
| 3356 | 8.0.0.0/9 | 16 | 9 | 134217728 | 142606335 | Level 3 Communications, Inc. |
| 15169 | 8.8.8.0/24 | 526344 | 24 | 134744064 | 134744319 | Google Inc. |
+-------+------------+-----------------+--------------+-----------+-----------+------------------------------+
3 rows in set (0.64 sec)
所需的方法类似于上一个查询减去网络掩码位的扫描.
解决方法:
主要问题是优化器不知道是否有一个匹配的起始端对或批次.因此,任何尝试优化的尝试都会遇到表扫描,或者至少是大范围扫描.
你必须从哪开始？ IP地址？还是CIDR阻止？我问这是因为我们可能需要重新排列您开始使用的数据,以便有效地查找其他数据.
在this中,我将解释如何构建和维护所有2 ^ 32(或IPv6等效)IP地址的表.它仅使用start_ip列,并从下一行推断出end_ip.这意味着所有未分配的IP范围必须在表中有一行. (这不是一个很大的负担,最多是行数加倍.)这样,几乎所有的操作基本上都是O(1) – 就像WHERE ip> = start_ip ORDER BY start_ip DESC LIMIT 1得到的回答“立即”.没有表扫描,没有范围扫描;没有什么比’点查询'(有效)更糟糕了.请注意,它甚至不需要测试end_ip.警告：不处理重叠范围.某些应用程序(可能不是您的应用程序)可以调整为不需要重叠.
如何适应CIDR？一种方法是将您的CIDR表转换为我的变体.你熟悉如何做到这一点;主要区别在于缺少end_ip和增加“非拥有”范围.因此,如果您“从”CIDR开始并需要查找IP,这是一个可能的答案.
标签：mysql,range-types,index,datatypes 来源： https://codeday.me/bug/20190806/1602890.html
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