From the Begin prompt with the DAL Tester or DAL Debugger, enter the command:
describe DBMS;
printall;
go
If DB2 isn't listed as a choice, then something is wrong with the DAL installation on the host. If DB2 is listed as an available DBMS, then try to open it with:
open DB2 DBMS;
go
If the DBMS opens successfully, then try:
describe databases;
printall;
go
A list of available subsystem IDs should appear. If nothing comes back, then the environment file is emplty or inaccessible.
Next, open the desired database and see what's in it with:
open db2 database '_____';
describe tables;
printall;
go
If the only tables listed are not correct, or if a -551 error is returned, see Appendix B of the "Data Access Language Server Installation and Operating Guide for MVS/TSO." Appendix B describes how to set up views for DAL users to access the DB2 tables.