Chapter 48. Overview of PostgreSQL Internals

Table of Contents
48.1. The Path of a Query
48.2. How Connections are Established
48.3. The Parser Stage
48.3.1. Parser
48.3.2. Transformation Process
48.4. The PostgreSQL Rule System
48.5. Planner/Optimizer
48.6. Executor

Author: This chapter originated as part of Enhancement of the ANSI SQL Implementation of PostgreSQL, Stefan Simkovics' Master's Thesis prepared at Vienna University of Technology under the direction of O.Univ.Prof.Dr. Georg Gottlob and Univ.Ass. Mag. Katrin Seyr.

This chapter gives an overview of the internal structure of the backend of PostgreSQL. After having read the following sections you should have an idea of how a query is processed. This chapter does not aim to provide a detailed description of the internal operation of PostgreSQL, as such a document would be very extensive. Rather, this chapter is intended to help the reader understand the general sequence of operations that occur within the backend from the point at which a query is received, to the point at which the results are returned to the client.