The official reference materials for PostgreSQL 9.0 include this manual. It covers the syntax, data types, functions and operators, indexes, and transactions of the SQL language standard as implemented by PostgreSQL.
In-depth documentation is also provided for PostgreSQL 9's new XML datatypes and full-text index capabilities. This book is a part of a collection. The documentation for each PostgreSQL command, from ABORT to VALUES, may be found in the standalone Volume 1B: SQL Command Reference (ISBN 978-1-906966-05-8). Volume 1B also contains documentation for the command-line clients and servers for PostgreSQL.
It is intended to use Volumes 1A and 1B together. Volume 2: Programming Guide (ISBN 978-1-906966-06-5) and Volume 3: Server Administration Guide are the two supplementary volumes in this series (ISBN 978-1-906966-07-2). The publisher, Network Theory Ltd., donates $1 to the PostgreSQL project for each copy of this manual that is sold.