Non-superuser script improvement suggestions

1. CREATE EXTENSION IF NOT EXISTS pg_stat_statements;
   

   This^^^ was missing in my database. (Also shared_preload_libraries = 'pg_stat_statements' was needed.)

2. All function names (i.e., not only view names) can be (and perhaps should be) schema-qualified, so that they are in the newly created schema and not in the default one.

3. I like to use UNIX domain sockets for all local PostgreSQL connections. This is feasible, but the hostname must be a directory, not localhost, which doesn’t play well with the most common postgresql:// URI format. Fortunately one can pass everything as parameter key words (after three slashes). For example, when my PostgreSQL socket is in /run/postgresql/.s.PGSQL.5432, then I could use:

   postgresql:///?dbname=postgres&user=postgres_exporter&password=CENSORED&host=/run/postgresql/&port=5432
   

   The only drawback is that settings like sslmode=verify-full have no effect with UNIX domain sockets, so one won’t get an automated test whether certificates and CRLs are up-to-date and working. This works with TCP only. If encrypted connections need to be checked this way, one would use TCP on [::1] (instead of a UNIX socket) and then sslcert=... and sslkey=... can be set in the URI to get client authentication working.

The issue names no files or tests. Start by locating the scripts that create the PostgreSQL extension, views, and functions, then inspect how PostgreSQL connection parameters are handled. Compare the current behavior with the requested non-superuser, schema-qualified, and UNIX-socket use cases before defining what completion requires.