SQL Application and Development: (9) Improving efficiency indexes and SQL Indexes
In a database, an index is a special object. It is a database structure that can accelerate data retrieval. It can quickly find the desired content from a large amount
Tips and notes for using mysql indexes, and tips for using mysql Indexes
I. Functions of Indexes
In general application systems, the read/write ratio is around, and insert operations and general update operations rarely encounter performance
One, what is the index
One of the best ways to reduce disk I/O and logical read times is to use the index
The index allows SQL Server to look up data in a table without having to scan the entire table.
1.1, the advantages of the index:
Become a
Index is the most important tool for improving the query speed. Of course there are other technologies available for use, but in general, the biggest performance difference is the correct use of indexes. In the MySQL Mail List, people often ask for
Brief Introduction to database indexes and simple database Indexes
Recently, I have asked a lot of questions about database indexes during the written test interview. Because I didn't perform a system review separately, many of the index knowledge
First, why do you want to create an index (advantage)?This is because creating an index can greatly improve the performance of the system.First, by creating a unique index, you can guarantee the uniqueness of each row of data in a database
Advantages and disadvantages of indexes
Why create an index? This is because creating an index can greatly improve the system performance. First, you can create a unique index to ensure the uniqueness of each row of data in the database table.
Why create an index? This is because creating an index can greatly improve the system performance. First, you can create a unique index to ensure the uniqueness of each row of data in the database table. Second, it can greatly speed up data
The following articles mainly introduce the disadvantages of MySQL indexes and the actual operations of MySQL indexes, which deserves our attention, we may not know that using indexes too much will lead to abuse.
The following articles mainly
Abstract: This article will introduce how to optimize the performance of the database system to process various queries as quickly as possible. The function of indexes in optimizing queries includes the principle of optimizing indexes. indexes are
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