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This article will explain in detail about the mysql index can be divided into several types, the editor thinks it is very practical, so share it for you to do a reference, I hope you can get something after reading this article.

What are the mysql indexes?

1. Primary key index: primary key index is a special unique index, and null values are not allowed.

2. General index or single-column index

3. Multi-column index (composite index): a composite index refers to an index created on multiple fields, and the index will be used only if the first field when the index is created is used in the query condition. Follow the leftmost prefix set when using a composite index

4. Unique index or non-unique index

5. Spatial index: spatial index is an index established on the fields of spatial data types. There are four spatial data types in MYSQL, namely GEOMETRY, POINT, LINESTRING and POLYGON. MYSQL is extended with the SPATIAL keyword to enable the syntax used to create regular index types to create spatial indexes. The column that creates a spatial index must be declared as NOT NULL. Spatial indexes can only be created in tables where the storage engine is MYISAM.

About the mysql index can be divided into several kinds to share here, I hope the above content can be of some help to you, can learn more knowledge. If you think the article is good, you can share it for more people to see.

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