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如何提高MySQL的搜索性能

[英]How to improve search performance in MySQL

I have a table that contains two bigint columns: beginNumber , endNumber , defined as UNIQUE . 我有一个包含两个bigint列的表: beginNumberendNumber ,定义为UNIQUE The ID is the Primary Key . IDPrimary Key

ID | beginNumber | endNumber | Name | Criteria

The second table contains a number. 第二个表包含一个数字。 I want to retrieve the record from table1 when the Number from table2 is found to be between any two numbers. 当发现table2中的数字位于任意两个数字之间时,我想从table1中检索记录。 The is the query: 是查询:

select distinct t1.Name, t1.Country
from t1
where t2.Number
BETWEEN t1.beginIpNum AND t1.endNumber

The query is taking too much time as I have so many records. 由于我有很多记录,因此查询花费了太多时间。 I don't have experience in DB. 我没有DB的经验。 But, I read that indexing the table will improve the search so MySQL does not have to pass through every row searching about m Number and this can be done by, for example, having UNIQE values. 但是,我读到对表建立索引将改善搜索,因此MySQL不必遍历每行有关m Number的搜索,这可以通过例如具有UNIQE值来完成。 I made the beginNumber & endNumber in table1 as UNIQUE. 我在表1中将beginNumberendNumber设为UNIQUE。 Is this all what I can do ? 这就是我所能做的吗? Is there any possible way to improve the time ? 有什么办法可以缩短时间? Please, provide detailed answers. 请提供详细的答案。

EDIT: 编辑:

table1: 表格1:

CREATE TABLE `t1` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `beginNumber` bigint(20) DEFAULT NULL,
  `endNumber` bigint(20) DEFAULT NULL,
  `Name` varchar(255) DEFAULT NULL,
  `Criteria` varchar(455) DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `beginNumber_UNIQUE` (`beginNumber`),
  UNIQUE KEY `endNumber_UNIQUE` (`endNumber `)
) ENGINE=InnoDB AUTO_INCREMENT=327 DEFAULT CHARSET=utf8

table2: 表2:

CREATE TABLE `t2` (
  `id2` int(11) NOT NULL AUTO_INCREMENT,
  `description` varchar(255) DEFAULT NULL,
  `Number` bigint(20) DEFAULT NULL,
  PRIMARY KEY (`id2`),
  UNIQUE KEY ` description _UNIQUE` (`description `)
) ENGINE=InnoDB AUTO_INCREMENT=433 DEFAULT CHARSET=utf8

This is a toy example of the tables but it shows the concerned part. 这是桌子的玩具示例,但显示了相关部分。

I'd suggest an index on t2.Number like this: 我建议在t2.Numbert2.Number一个索引,如下所示:

ALTER TABLE t2 ADD INDEX numindex(Number);

Your query won't work as written because it won't know which t2 to use. 您的查询无法按书面要求运行,因为它不知道要使用哪个t2。 Try this: 尝试这个:

SELECT DISTINCT t1.Name, t1.Criteria
FROM t1 
WHERE EXISTS (SELECT * FROM t2 WHERE t2.Number BETWEEN t1.beginNumber AND t1.endNumber);

Without the t2.Number index EXPLAIN gives this query plan: 没有t2.Number索引,EXPLAIN给出以下查询计划:

1   PRIMARY t1  ALL                 1   Using where; Using temporary
2   DEPENDENT SUBQUERY  t2  ALL                 1   Using where

With an index on t2.Number, you get this plan: 使用t2.Number的索引,您可以获得以下计划:

PRIMARY t1  ALL                 1   Using where; Using temporary
DEPENDENT SUBQUERY  t2  index   numindex    numindex    9       1   Using where; Using index

The important part to understand is that an ALL comparison is slower than an index comparison. 要理解的重要部分是, ALL比较比index比较慢。

This is a good place to use binary tree index (default is hashmap). 这是使用二叉树索引的好地方(默认为hashmap)。 Btree indexes are best when you often sort or use between on column. 当您经常在列之间进行排序或使用时,Btree索引是最好的。

CREATE INDEX index_name 创建索引index_name

ON table_name (column_name) ON table_name(column_name)

USING BTREE 使用BTREE

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