Mysql Order By Two Fields

MySQL optimization is very important. The most common and most needed optimization is limit. 　　The limit of MySQL brings great convenience to paging, but when the amount of data is large, the performance of limit is reduced dramatically. The same is 10 data select * FROM Yanxue8_visit limit 10000,10 and select * from Yanxue8_visit limit 0,10 is not a quantitative level ...

Usually when we use the MySQL database, often because of operational errors caused by data loss, MySQL database backup can help us to avoid due to various reasons, data loss or other problems with the database. First, the data backup shortcut Because this method has not been the official official document validation, we tentatively called the experiment. Purpose: Backup hostA host a MySQL database backup TestA, and restored to the hostB machine in the test environment: Operating System: WinNT4.0, Mysql3.22.34, phpM ...

First, the importance of the index The index is used to quickly find a column in a particular value of the line. Instead of using an index, MySQL must start with the first record and then read the entire table until it finds the relevant row. The larger the table, the more time it takes. If the table in the query column index, MySQL can quickly reach a location to search the middle of the data file, there is no need to see all the data. Note that if you need to access most of the rows, sequential reads are much faster since we avoid disk searches. If you use Xinhua Dictionary to find "Zhang" the Chinese characters, do not use the directory, then ...

MySQL Chinese wrong order solution / * The method has been changed to the character set of the field gbk, and then the order by order can be used directly. For example, change "name char (10)" to "name char (10) binary" by adding the "binary" attribute to the field containing Chinese and setting it as binary. ". If you make ...

Operation database is the basis of dynamic Web programming, this article gives you a detailed description of how PHP operates MySQL database 1. Establish and close connection 1 mysql_connect () resource mysql_connect ([string hostname [:p ort][:/path/to/socket][,string username] [, String Passwor ...

In this lesson, we want to learn how to increase the intelligent processing capacity of the Web page. Basic functions Welcome to the third and final lesson of this tutorial. If you've learned the first and second lessons, you've mastered the basics of installing and programming MySQL and PHP. Here are some of the other functions of PHP that might be useful to you and make your development process simpler. 　　First, let's look at the document. You should know some basic concepts of the header file, right? The header file is an external file whose contents are included in the main program. ...

It is well known that the system reads data from memory hundreds of times times faster than it does from the hard disk. So now most of the application system, will maximize the use of caching (in memory, a storage area) to improve the system's operational efficiency. MySQL database is no exception. 　　Here, the author will combine their own work experience, with you to explore the MySQL database Cache management skills: How to properly configure the MySQL database cache, improve cache hit rate. 　　When will the application get the data from the cache? Database read from server ...

In 2017, the double eleven refreshed the record again. The transaction created a peak of 325,000 pens/second and a peak payment of 256,000 pens/second. Such transactions and payment records will form a real-time order feed data stream, which will be imported into the active service system of the data operation platform.

Intermediary transaction http://www.aliyun.com/zixun/aggregation/6858.html ">seo diagnose Taobao guest cloud host technology Hall of the current web2.0 program, a big bottleneck is the database swallow metric." 　　However, how to determine the bottleneck of the system is a database, because only to determine the database is the bottleneck of the entire system, we have to optimize him, after all, there are so many needs to wait for us to do. 　　How do I determine that a database is a bottleneck? ...

Recently, the domestic well-known cms/shop system developers Easy Network released its march. NET platform's flagship product: Sitefactory Cms/eshop 1.0. May be because of the popularity of the dynamic CMS is too high, so it's shop system has not been very good to promote, nor was the vast number of netizens webmaster good understanding. In fact, moving easily eshop products is absolutely a very powerful online shop system, not more than shopex such a professional only do shop system products inferior to a few, while in the CMS section, moving Easy eshop ...