---
title: "PostgreSQL Joins: A Summary"
description: "SQL joins are used to combine rows from two or more tables based on a related column between them. Let’s learn how to use them in PostgreSQL."
section: "Postgres basics"
---

> **TimescaleDB is now Tiger Data.**

# 

SQL joins are used to combine rows from two or more tables based on a related column between them. There are four types of SQL joins: **INNER JOINS **(returns records with matching values in both tables), **LEFT JOINS** (returns all records from the left table, and matched records from the right table), **RIGHT JOINS** (returns all records from the right table, and matched records from the left table), and **FULL JOINS** (returns all records when there is a match in either the left or the right table).

Let’s dive into each of these and learn how to use them in PostgreSQL (and, of course, Timescale!).

- [What Is a PostgreSQL Left Join? And a Right Join?](#)
- [What Is a PostgreSQL Full Outer Join?](#)
- [What Is a PostgreSQL Inner Join?](#)
- [What Is a PostgreSQL Cross Join?](#)



## Learn More About Join Strategies to Enhance Your Database Performance

Understanding how the PostgreSQL parser picks a join method can be valuable to define join strategies to enhance your database performance. To learn more about this topic and take your knowledge of joins to another level, check out this article on [PostgreSQL Join Type Theory](#).