The following are some optional packages that you may want to have installed:

GNU Readline Library

The GNU Readline library greatly increases the usability of psql , the standard PostgreSQL command-line console client. It adds all of the standard functionality of the GNU Readline library to the psql command line, such as being able to easily modify, edit and retrieve command history information with the arrow keys, and reverse-i-search. If the Readline libraries are already installed on your system, the configuration process should automatically compile readline support with psql .

Note NetBSD Users

You may not need this package if you have NetBSD, as NetBSD has a libedit library which provides readline compatibility.


OpenSSL is an Open Source implementation of the SSL/TLS protocols. OpenSSL is commonly used with utilities such as OpenSSH and Apache-SSL. PostgreSQL can make use of OpenSSL for encrypted connectivity between the psql client application and the PostgreSQL backend. You may also want to consider OpenSSL if you wish to use Stunnel which is discussed later on in the book. You can find out more information on OpenSSL at:


TCL/TK is a combination programming language and graphical toolkit. Although we don't cover extensive use of TCL with PostgreSQL, we do cover the use of PgAccess. If you wish to utilize the PgAccess application you will need to install the TCL/TK software. The website for TCL/TK is:


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