This article analyzes the php+mysql query optimization method through examples. Share it with everyone for your reference. The specific analysis is as follows:
PHP+Mysql is the most commonly used golden partner. When used together, they can achieve the best performance. Of course, if used together with Apache, it will be even more perfect.
Therefore, it is necessary to optimize mysql queries. The following is a simple example to show the impact of different SQL statements on query speed.
There is such a table test, which has an auto-incremented id as the main index. Now to query the records whose id numbers are within a certain range, you can use the following SQL statement:
The reason is that although there is already an index on the id attribute, sorting is still a very expensive operation and should be used with caution. The second statement allows MySql to make full use of the information already created in the database. B+ tree index, so the search speed is quite fast, hundreds of times faster than the original.
It can be seen that website developers must be careful when using SQL statements, because a careless SQL statement may cause your website access speed to drop sharply, put the backend database under tremendous pressure, and quickly fall into a trap. The dilemma of being unable to open the page.
I hope this article will be helpful to everyone’s php+mysql program design.