Mastering PostgreSQL 9.6

Checking for available extensions

PostgreSQL offers various views to figure out which extensions are there on the system and which ones are actually deployed. One of those views is pg_available_extensions:

test=# \d pg_available_extensions  View "pg_catalog.pg_available_extensions"       Column       | Type | Modifiers  -------------------+------+-----------  name              | name |   default_version   | text |   installed_version | text |   comment           | text |  

It contains a list of all extensions available, including their names, their default version, and the version currently installed. To make it easier to the end user, there is also a description available, telling us more about the extension.

The following listing contains two lines taken from pg_available_extensions ...