PostgreSQL for Data Architects

Working with extensions

We have so far initialized the database cluster. However, we made quite a few extensions available using the world option. What about them? We can list the installed extensions using the dx (describe extension) command at the psql prompt:

postgres=# \dx
                 List of installed extensions
  Name   | Version |   Schema   |         Description          
---------+---------+------------+------------------------------
plpgsql | 1.0     | pg_catalog | PL/pgSQL procedural language
(1 row)

To get a list of available extensions, we can query the pg_available_extensions view, as shown here:

postgres=# SELECT name,comment  FROM pg_available_extensions limit 5;
   name   |                           comment                         
----------+--------------------------------------------------------------
dblink | connect ...