wip -- dbg pg app client usage

hack/fuse-demo/mock_application_pg.sh

@@ -26,13 +26,17 @@ PG_SU=postgres
 PG_U=testpguser
 PG_DB=testdb
 
+# aside: postgres defaults to UNIX (filesystem) socket at /var/run/postgresql/*,
+#   not IP (network) socket, so it's the client's responsibility to ensure that
+#   the conn is opened at the network location
+
 print -- "CREATE ROLE ${PG_U} WITH LOGIN CREATEDB;
 CREATE DATABASE ${PG_DB} WITH OWNER ${PG_U};" | \
-    psql -p $MY_PG_PORT -U $PG_SU
+    psql -h localhost -p $MY_PG_PORT -U $PG_SU
 
 
 run_sql() {
-    print -- "$1" | psql -p $MY_PG_PORT -U ${PG_U} ${PG_DB}
+    print -- "$1" | psql -h localhost -p $MY_PG_PORT -U ${PG_U} ${PG_DB}
 }
 
 run_sql 'CREATE TABLE tabla_e (