Chapter 43. Overview of PostgreSQL Internals

Table of Contents
43.1. The Path of a Query
43.2. How Connections are Established
43.3. The Parser Stage
43.3.1. Parser
43.3.2. Transformation Process
43.4. The PostgreSQL Rule System
43.5. Planner/Optimizer
43.6. 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.