Murali...I too read somewhere that we can use SYSCAT.TABLES for that. But I tried to do a select on this table and ended up with SQLCODE = -204, ERROR: SYSCAT.TABLES IS AN UNDEFINED NAME.
Raju, Generating the DDL for the alias, will give the Create statement of that alias from which we can check the base table name..I am just trying to check for such a JCL. Will let you know, in case I find it.