MySQL index details, MySQL index detailsI. Introduction to index basics 1.1
In MySQL, indexes are also called keys. They are a data structure that the storage engine uses to quickly find records.
Indexes are critical to good performance. Especially
ReprintedBytes
IndexYou can use indexes to quickly access specific information in database tables. An index is a structure that sorts the values of one or more columns in a database table (for example, the last name (lname) column of the employee
MySQL 5-1 -- index bitsCN.com 1. MySQL has multiple rows that access tables. The most commonly used is sequential access and index access. Sequential access refers to browsing a table in one row, that is, full table scan. Disadvantage: it is very
As a free and efficient database, MySQL is basically the first choice. Good security connection, with query resolution, SQL statement optimization, use of Read and write locks (refinement to line), things isolation and multiple version concurrency
1. MySQL has multiple rows that access tables. The most commonly used rows are sequential access and index access. Sequential access refers to browsing a table in one row, that is, full table scan. Disadvantage: It is very time-consuming and
This article mainly originates from the Internet mainstream article, just according to the individual understanding slightly makes the integration, behind has the reference link. I. Summary
This paper takes the MySQL database as the research object
Index optimization for mysql performance optimization,
As a free and efficient database, mysql is the first choice. Good secure connection, built-in query parsing, SQL statement optimization, use read/write locks (refined to rows), transaction
We will first discuss the index, because it is the most important tool to speed up the query. Of course there are other technologies to speed up the query, but the most effective is to use the index properly. Next we will introduce what the index is,
Unique indexIf the primary key is not set to a clustered index when it is created, it must be a unique nonclustered index. In fact, the unique index, the name Incredibles, is that it requires the value on that column to be unique. A unique index
062 Creating an indexIndexing is especially important for queries that are the primary application. A lot of times the performance problem is simply because we forgot to add an index, or we didn't add a more efficient index. If you do not index,
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