The book "PostgreSQL 8.4 Official Documentation - Volume III. Server Programming" is the part of the official documentation for PostgreSQL 8.4.

To make the large amount of information about PostgreSQL manageable, this information has been organized in several volumes. Each volume is targeted at a different class of users, or at users in different stages of their PostgreSQL experience:

Volume III consists from:

• Part V - contains information for advanced users about the extensibility capabilities of the server. Topics include user-defined data types and functions.