~/minetest % rg 'pgsql.*conn' -C 1
src/server.cpp
4445-		std::string connect_string;
4446:		world_mt.getNoEx("pgsql_mod_storage_connection", connect_string);
4447-		return new ModStorageDatabasePostgreSQL(connect_string);

src/servermap.cpp
651-		std::string connect_string;
652:		conf.getNoEx("pgsql_connection", connect_string);
653-		db = new MapDatabasePostgreSQL(connect_string);

src/serverenvironment.cpp
1869-		std::string connect_string;
1870:		conf.getNoEx("pgsql_player_connection", connect_string);
1871-		return new PlayerDatabasePostgreSQL(connect_string);
--
1996-		std::string connect_string;
1997:		conf.getNoEx("pgsql_auth_connection", connect_string);
1998-		return new AuthDatabasePostgreSQL(connect_string);

doc/world_format.md
171-
172:    pgsql_connection = host=127.0.0.1 port=5432 user=mt_user password=mt_password dbname=minetest
173:    pgsql_player_connection = (same parameters as above)
174:    pgsql_readonly_connection = (same parameters as above)
175:    pgsql_auth_connection = (same parameters as above)
176:    pgsql_mod_storage_connection = (same parameters as above)
177-

src/database/database-postgresql.cpp
31-		std::string msg =
32:			"Set pgsql" + s + "_connection string in world.mt to "
33-			"use the postgresql backend\n"
34-			"Notes:\n"
35:			"pgsql" + s + "_connection has the following form: \n"
36:			"\tpgsql" + s + "_connection = host=127.0.0.1 port=5432 "
37-			"user=mt_user password=mt_password dbname=minetest" + s + "\n"