tpch1s=# select * from pg_available_extensions;
          name          | default_version | installed_version |                           comment                            
------------------------+-----------------+-------------------+--------------------------------------------------------------
 plpythonu              | 1.0             |                   | PL/PythonU untrusted procedural language
 citext                 | 1.3             |                   | data type for case-insensitive character strings
 file_fdw               | 1.0             |                   | foreign-data wrapper for flat file access
 fuzzystrmatch          | 1.1             |                   | determine similarities and distance between strings
……