PostgreSQL 10 Administration Cookbook

How to do it…

1. First, we list all the available extensions:

postgres=# \x onExpanded display is on.postgres=# SELECT *postgres-# FROM pg_available_extensionspostgres-# ORDER BY name;-[ RECORD 1 ]-----+--------------------------------------------------name              | adminpackdefault_version   | 1.0installed_version |comment           | administrative functions for PostgreSQL-[ RECORD 2 ]-----+--------------------------------------------------name              | pg_stat statementsdefault_version   | 1.5installed_version |comment           | track execution statistics of all SQL statements executed(...)

In particular, if the dblink extension is installed, then we see a record like this:

-[ RECORD 10 ]----+--------------------------------------------------name              | dblinkdefault_version | ...