This is the official documentation of PostgreSQL version 11.2. The manual is 2,816 pages long, and has been split into three volumes.The volume ISBN numbers are: Volume One 9781680922738, Volume Two 9781680922745 and Volume Three 9781680922752.Volume One covers chapters Chapters 1-36. Volume Two covers Chapters 37-50 & the Reference section. Volume Three covers Chapters 51-70 & the Appendixes.Each volume as the full Preface, Bibliography and Index sections.This book has been written by the PostgreSQL developers and other volunteers in parallel to the development of the PostgreSQL software. It describes all the functionality that the current version of PostgreSQL officially supports.To make the large amount of information about PostgreSQL manageable in printed form, this book is organized in several parts. Each part is targeted at a different class of users, or at users in different stages of their PostgreSQL experience: Part I is an informal introduction for new users. Part II documents the SQL query language environment, including data types and functions, as well as user-level performance tuning. Every PostgreSQL user should read this. Part III describes the installation and administration of the server. Everyone who runs a PostgreSQL server, be it for private use or for others, should read this part. Part IV describes the programming interfaces for PostgreSQL client programs. Part V contains information for advanced users about the extensibility capabilities of the server. Topics include user-defined data types and functions. Part VI contains reference information about SQL commands, client and server programs. This part supports the other parts with structured information sorted by command or program. Part VII contains assorted information that might be of use to PostgreSQL developers.You may download the original document as a PDF for free from Postgresql.org.