How to create composite index in MySQL?

To create a composite index in MySQL, follow these steps:

1. Select the table for which you need to create a composite index.

USE database_name;

1. Create a composite index using the CREATE INDEX statement.

CREATE INDEX index_name ON table_name (column1, column2, column3, ...);

In this, index_name refers to the name of the index, table_name to the name of the table, and column1, column2, column3, etc., refer to the names of the columns to be included in the composite index. Please specify the correct column names and index name as needed.

1. Optional: Use the DESCRIBE statement to verify if the composite index has been successfully created.

DESCRIBE table_name;

The DESCRIBE statement will display the structure of the table, including index information. Make sure that the composite index is correctly created and includes the required columns.

Important notes:

1. Please carefully select the columns that need to be included in the composite index. The composite index should include columns commonly used for filtering and sorting to improve query performance.
2. Creating composite indexes may consume a certain amount of storage space. Please make sure there is enough storage space to support the creation of the indexes.
3. Before creating a composite index, evaluate the query performance and requirements in the database to determine if a composite index is necessary.