SELECT extversion FROM pg_extension WHERE extname = 'nominatim_fdw';
 extversion 
------------
 1.0
(1 row)

CREATE SERVER osm 
FOREIGN DATA WRAPPER nominatim_fdw 
OPTIONS (url 'https://nominatim.openstreetmap.org');
ALTER EXTENSION nominatim_fdw UPDATE TO '1.1';
SELECT extversion FROM pg_extension WHERE extname = 'nominatim_fdw';
 extversion 
------------
 1.1
(1 row)

ALTER EXTENSION nominatim_fdw UPDATE TO '1.2';
SELECT extversion FROM pg_extension WHERE extname = 'nominatim_fdw';
 extversion 
------------
 1.2
(1 row)

/* verify functions are still callable after upgrade */
SELECT nominatim_fdw_version() IS NOT NULL;
 ?column? 
----------
 t
(1 row)

DROP SERVER osm CASCADE;