Section No. 288, MySQL database-index

MySQL Database-index

Index is a data structure in the database that is designed to help users quickly query data. Similar to a directory in a dictionary, you can find the contents of the dictionary based on the directory to locate the data, and then get directly.

If the index lookup data is not created, it is a full-table scan, that is, to look up the dictionary like no directory, a page by page to the target data location, so that if the data volume assembly is quite time-consuming,

Indexing is a quick way to help users find target data, saving time

Introduction to Indexes

An index is a tree structure that stores data in a b+tree way.

For more information, you can search online for b+tree

Common indexes in MySQL are:

Normal index
Unique index
Primary key Index
Combined index
Full-Text Indexing

Section No. 288, MySQL database-index