Indexes in MySQL are special data structures that store information about the values of table fields. They are used to improve the speed of searching and retrieving records from a table.
What are indexes used for?
Indexes are used for the following tasks:
Searching for records by the value of one or more fields. For example, if you need to find all users with a certain name, you can use an index for the name field.
Retrieving records from a table that meet certain criteria. For example, if you need to retrieve all users who registered after a certain date, you can use an index for the created_at field.
Sorting records by the value of one or more fields. For example, if you need to sort users by name, you can use an index for the name field.
Advantages of indexes
Indexes have a number of advantages, including:
Improve the speed of searching and retrieving records.
Reduce the load on the database server.
Increase the efficiency of query execution.
Disadvantages of indexes
Indexes also have a number of disadvantages, including:
Increase the size of the table.
Reduce the efficiency of query execution that do not use an index.
