As far as I know, DP 8.1 has the same level of license restriction that previous versions had. DP reads the cell_info file, starting from the top. Whenever it sees an Application Integration component (MSSQL< Exchange, Oracle, Sybase, Informaix, DB2, probably a few others), it check to see if there are sufficient on-line extension licenses
Hostnames at the top of the cell_info file get the licenses. Hostnames further on down, when the amount of Servers having Application integration components installed exceed the number of On-Line extension licenses, don't get the licenses