Mysql Indexing For Performance

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 ...

As the most popular open source database, MySQL is widely used in Web applications and other small and medium-sized projects. However, in many large IT companies, MySQL has gradually deviated from the original open source version after being highly optimized and customized, more like a branch, such as the Webscalesql of Facebook, which was not long ago open source. 　　Recently, Mr. Xiong has published a blog post, from the perspective of large-scale web site architecture development of the changes in MySQL application, here for you to share. This article mainly describes the different and ...

In the development of friends especially and MySQL have contact friends will encounter sometimes MySQL query is very slow, of course, I refer to the large amount of data millions level, not dozens of, the following we take a look at the resolution of the query slow way. -Often find developers looking up statements that are not indexed or limit n, which can have a significant impact on the database, such as a large table of tens of millions of records to scan all, or do filesort, and the database and server IO impact. This is the case above the mirrored library. And ...

1, use the index to traverse the table faster. The index created by default is a non-clustered index, but sometimes it is not optimal. Under non-clustered indexes, the data is physically stored on the data page. Reasonable index design should be based on the analysis and prediction of various inquiries. In general: a. A large number of duplicate values, and often range query (>, <,> =, <=) and order by, group by occurred column, consider the establishment of cluster index; b. Column, ...

1, use the index to traverse the table faster. The index created by default is a non-clustered index, but sometimes it is not optimal. Under non-clustered indexes, the data is physically stored on the data page. Reasonable index design should be based on the analysis and prediction of various inquiries. In general: a. There are a large number of duplicate values, and often range query (>, <,> =, <=) and order by, group by occurred columns, consider the establishment of cluster index; Column, and each column contains duplicate values ​​can be ...

Several guidelines on the establishment of the index: 1, a reasonable indexing can speed up the efficiency of data reading, but unreasonable indexing will slow down the database response speed. 2, the more the index, the slower the update data. 3, try to use the index when using MyIsam as an engine (because MySQL uses BTree to store indexes), not InnoDB. But MyISAM does not support Transcation. 4, when your program and database structure / SQL statement has been optimized to the extent that can not be optimized, and the program bottleneck can not be successfully resolved, then ...

NoSQL has been in vogue for a long time, so what exactly is the scene you need to use these "emerging things", such as http://www.aliyun.com/zixun/aggregation/13461.html ">mongodb?" Here are some summaries: you expect a higher write load by default, compare transaction security, MongoDB more attention to high insertion speed. If you need to load a lot of low-value business data, then MONGO ...

As a software developer or DBA, one of the essential tasks is to deal with databases, such as MS SQL Server, MySQL, Oracle, PostgreSQL, MongoDB, and so on. As we all know, MySQL is currently the most widely used and the best free open source database, in addition, there are some you do not know or useless but excellent open source database, such as PostgreSQL, MongoDB, HBase, Cassandra, Couchba ...

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? ...

Several years of work down, also used several kinds of database, accurate point is "database management system", relational database, there are nosql. Relational database: 1.MySQL: Open source, high performance, low cost, high reliability (these features tend to make him the preferred database for many companies and projects), for a large scale Web application, we are familiar with such as Wikipedia, Google, and Facebook are the use of MySQL. But the current Oracle takeover of MySQL may give us the prospect of using MySQL for free ...