I've installed PostGIS (ver. 2.0.1) on my Mac using EnterpriseDB's StackBuilder, which I also used for my PostgreSQL (9.2.2) installation. Although StackBuilder says that PostGIS is now installed, and although I have a PostGIS directory in /usr/local/PostgreSQL/9.2/, it doesn't appear to be actually installed (see queries below).
gregory=# select postgis_full_version();
ERROR: function postgis_full_version() does not exist
LINE 1: select postgis_full_version();
^
HINT: No function matches the given name and argument types. You might need to add explicit type casts.
gregory=# create extension postgis;
ERROR: could not open extension control file "/usr/local/PostgreSQL/9.2/share/postgresql/extension/postgis.control": No such file or directory
and select * from pg_available_extensions;
does not return a record for PostGIS.
Does anyone know what's up with this and how to get it to work?