SELECT version();
SELECT now();

SHOW config_file;       -- /var/lib/postgresql/data/postgresql.conf
SHOW data_directory;    -- /var/lib/postgresql/data
SHOW hba_file;          -- /var/lib/postgresql/data/pg_hba.conf
    -- host-based authentication
    -- https://www.postgresql.org/docs/current/static/auth-pg-hba-conf.html
SHOW ident_file;        -- /var/lib/postgresql/data/pg_ident.conf
    -- user name mapping: SYSTEM-USERNAME PG-USERNAME
SHOW external_pid_file;

docker run -p 80:80 \
-e "PGADMIN_DEFAULT_EMAIL=user@domain.com" \
-e "PGADMIN_DEFAULT_PASSWORD=SuperSecret" \
-d dpage/pgadmin4

SELECT usename FROM pg_user;
CREATE USER fzinfz;
\password fzinfz
ALTER USER fzinfz WITH SUPERUSER;
\du
    -- list user/role

CREATE database tutorial;
\c tutorial
psql -U postgres -h localhost -d tutorial