proc dbOpen(_: type PostgreSQL; database: string; user: string;
            password: string; host: string; port: int; maxConnections = 1;
            timeout = 30; shouldDisplayLog = false; shouldOutputLogFile = false;
            logDir = ""): PostgresConnections

proc dbOpen(_: type PostgreSQL; databaseUrl: DatabaseUrl;
            maxConnections: int = 1; timeout = 30; shouldDisplayLog = false;
            shouldOutputLogFile = false; logDir = ""): PostgresConnections

proc dbOpen(_: type PostgreSQL; url: string; maxConnections: int = 1;
            timeout = 30; shouldDisplayLog = false; shouldOutputLogFile = false;
            logDir = ""): PostgresConnections