MySQL Indexing Explained: How It Works

MySQL index is a type of data structure that speeds up the process of searching and retrieving data in a database by creating a separate data structure that associates column values in a data table with their corresponding row locations for faster data retrieval.

In specific terms, MySQL indexes will sort values based on specified columns or combination of columns and store these sorted values in a B-tree or hash table. When searching for specific data, MySQL will first locate the data that meets the conditions based on the index structure, and then retrieve the data content directly through pointers or row positions, avoiding full table scans and improving query speed.

Furthermore, MySQL indexes can also help optimize query operations in the database system, reduce disk I/O operations, and improve query performance. However, it is important to note that having too many indexes can increase storage space and the cost of write operations, so it is necessary to design and manage indexes wisely based on the actual situation.