通过索引查询慢速搜索LIKE％MYSQL

i have table with 100 000 000 rows so large. Structure of table

我有100万行这么大的表。表的结构

id         int          INDEX(not primary not unique just index)
lang_index varchar(5)   INDEX
name       varchar(255) INDEX
enam       varchar(255) INDEX

Ok. i do query

好。我查询

1 Query

1查询

"SELECT name FROM table WHERE lang_index='en' AND name LIKE 'myname%'"

Speed is ok for this large table. around 0.02 sec.

这张大桌的速度还可以。大约0.02秒。

i try 2 Query

我尝试2查询

"SELECT name FROM table WHERE lang_index='en' AND (name LIKE 'myname%' OR enam LIKE 'myname%')"

Very very slow around 230 sec!!!

在230秒左右非常慢！

then i try this 3 Query

然后我尝试这3个查询

"SELECT name FROM table WHERE lang_index='en' AND enam LIKE 'myname%'"

Speed is fantastic. around 0.02 sec.

速度太棒了。大约0.02秒。

Then i explode my 2nd query for two queries (1 and 3 query) its faster. around 0.04 sec but it not simply.

然后我更快地爆炸我的第二个查询两个查询（1和3查询）。大约0.04秒但不简单。

Why my query is slow? Two queries much faster than one. I need do this "SELECT name FROM table WHERE lang_index='en' AND (name LIKE 'myname%' OR enam LIKE 'myname%')" How i can make it faster?

为什么我的查询很慢？两个查询比一个查询快得多。我需要这样做“SELECT name FROM table WHERE lang_index ='en'AND（name LIKE'myname％'或enam LIKE'myname％'）”我怎样才能让它更快？

1 个解决方案

#1

The OR keyword drives MySQL's optimizer crazy.

OR关键字让MySQL的优化器变得疯狂。

You might try something like this.

你可能会尝试这样的事情。

SELECT name FROM table WHERE lang_index='en' AND name LIKE 'myname%'
UNION
SELECT name FROM table WHERE lang_index='en' AND enam LIKE 'myname%'

Or you might consider FULLTEXT searching if you can (if your table has MyISAM for access).

或者您可以考虑使用FULLTEXT搜索（如果您的表具有MyISAM用于访问）。

EDIT* It's hard to know exactly what's going on with these optimization things. Can you try this? This will see whether the language selection is fouling you up.

编辑*很难确切知道这些优化事情究竟发生了什么。你能试试吗？这将看到语言选择是否会影响你。

 SELECT name 
   FROM table 
  WHERE (name LIKE 'myname%' OR enam LIKE 'myname%')

Can you try this?

你能试试吗？

SELECT name FROM table WHERE lang_index='en' AND name LIKE 'myname%'
UNION ALL
SELECT name FROM table WHERE lang_index='en' AND enam LIKE 'myname%'

It won't give a perfect result -- it will have duplicate name items -- but it will skip a DISTINCT deduplicating step in your query.

它不会给出完美的结果 - 它将具有重复的名称项 - 但它将跳过查询中的DISTINCT重复数据删除步骤。

You might also try this.

你也可以试试这个。

SELECT name 
  FROM table
 WHERE lang_index='en'
   AND id IN (
    SELECT id from table 
     WHERE (name LIKE 'myname%' OR enam LIKE 'myname%'))

#1