This is the port for all stuff that comes in the contrib subtree of
the postgresql distribution. This subtree contains porting tools,
analysis utilities, and plug-in features that are not part of the core
PostgreSQL system, mainly because they address a limited audience or
are too experimental to be part of the main source tree.  This does
not preclude their usefulness.

Each subdirectory contains a README file with information about the
module. Some directories supply new user-defined functions, operators,
or types.  After you have installed the files you need to register the
new entities in the database system by running the commands in the
supplied .sql file.  For example,

        $ psql -d dbname -f module.sql

The .sql files are installed into /usr/local/share/postgresql/contrib

For more information, please see
/usr/local/share/doc/postgresql/contrib/README*

This software is part of the standard PostgreSQL distribution.