Chapter 42. Overview of PostgreSQL Internals

Table of Contents
42.1. The Path of a Query
42.2. How Connections are Established
42.3. The Parser Stage
42.3.1. Parser
42.3.2. Transformation Process
42.4. The PostgreSQL Rule System
42.5. Planner/Optimizer
42.6. 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.