Another strength of PostgreSQL is its extensibility. Extensibility was one of the original design goals, going back to the late 1980s. Now, in PostgreSQL 9.4, there are many additional modules that plug into the core PostgreSQL server.
There are many kinds of additional module offerings, such as the following:
Additional functions
Additional data types
Additional operators
Additional indexes
Note
Note that many tools and client interfaces work with PostgreSQL without any special installation. Here, we are discussing modules that extend and alter the behavior of the server beyond its normal range of SQL Standard syntax, functions, and behavior.
The procedure that makes a module usable is actually a two-step process. First, you install the module's files on your system so that they become available to the database server. Next, you connect to the database (or databases) where you want to use the module, and create the required objects. The first step is discussed...