Using Indexes to Improve Query Performance

An index in a database is a data structure that allows faster data retrieval from a table. When we run a query, the database uses the index to quickly locate the requested information instead of scanning through every row in the table. PostgreSQL indexes can significantly improve our database queries’ speed and efficiency. They do this by storing a sorted list of values for a particular column, allowing faster data lookup and retrieval.

It’s important to note that creating an index does come at a cost—it takes up additional storage space and can slow down data insertion and updates. Therefore, it’s important to carefully assess the benefits of an index for a particular query before creating one.

Types of indexes

Types of indexes in PostgreSQL include B-tree, hash, GiST, and GIN.

• B-Tree: This is the most commonly used type of index in PostgreSQL. It’s useful for supporting queries on a range of data values (e.g., WHERE x > 5 AND x < 10) and can also support partial matches (e.g., WHERE ...