Postgres: Extensions

-- list installed extensions in current database
\dx

-- List installed extensions in current system
SELECT * FROM pg_extensions;

-- List extensions available for install
SELECT * FROM pg_available_extensions;

-- Install extension
CREATE EXTENSION IF NOT EXISTS pg_stat_statements;

-- Comment on a extension
COMMENT ON EXTENSION pg_stat_statements IS 'track planning and execution statistics of all SQL statements executed';

Upgrade your extension:

ALTER EXTENSION ext UPDATE;

List functions in an extension (Replace pgcrypto):

SELECT e.extname, np.nspname AS proschema, p.proname as function
FROM pg_catalog.pg_extension AS e
    INNER JOIN pg_catalog.pg_depend AS d ON (d.refobjid = e.oid)
    INNER JOIN pg_catalog.pg_proc AS p ON (p.oid = d.objid)
    INNER JOIN pg_catalog.pg_namespace AS ne ON (ne.oid = e.extnamespace)
    INNER JOIN pg_catalog.pg_namespace AS np ON (np.oid = p.pronamespace)
WHERE d.deptype = 'e' AND e.extname = 'pgcrypto'
ORDER BY e.extname, function ASC ;