II. Server Programming

This second part of the manual explains the PostgreSQL approach to extensibility and describe how users can extend PostgreSQL by adding user-defined types, operators, aggregates, and both query language and programming language functions. After a discussion of the PostgreSQL rule system, we discuss the trigger and SPI interfaces.

Table of Contents

7. Architecture

7.1. PostgreSQL Architectural Concepts

8. Extending SQL: An Overview

8.1. How Extensibility Works

8.2. The PostgreSQL Type System

8.3. About the PostgreSQL System Catalogs

9. Extending SQL: Functions

9.1. Introduction

9.2. Query Language (SQL) Functions

9.3. Procedural Language Functions

9.4. Internal Functions

9.5. C Language Functions

9.6. Function Overloading

9.7. Table Functions

9.8. Procedural Language Handlers

10. Extending SQL: Types

11. Extending SQL: Operators

11.1. Introduction

11.2. Example

11.3. Operator Optimization Information

12. Extending SQL: Aggregates

13. The Rule System

13.1. Introduction

13.2. What is a Query Tree?

13.3. Views and the Rule System

13.4. Rules on INSERT, UPDATE and DELETE

13.5. Rules and Permissions

13.6. Rules and Command Status

13.7. Rules versus Triggers

14. Interfacing Extensions To Indexes

14.1. Introduction

14.2. Access Methods and Operator Classes

14.3. Access Method Strategies

14.4. Access Method Support Routines

14.5. Creating the Operators and Support Routines

14.6. Creating the Operator Class

14.7. Special Features of Operator Classes

15. Index Cost Estimation Functions

16. Triggers

16.1. Trigger Definition

16.2. Interaction with the Trigger Manager

16.3. Visibility of Data Changes

16.4. Examples

17. Server Programming Interface

17.1. Interface Functions

17.2. Interface Support Functions

17.3. Memory Management

17.4. Visibility of Data Changes

17.5. Examples