What is deadlock ?

A deadlock occurs when transaction 1 places a lock on resource A, and then needs to lock resource B. But resource B has already been locked by transaction 2, which in turn needs to place a lock on resource A. This state of affairs is called a deadlock or a deadly embrace. To resolve a deadlock, Teradata Database aborts one of the transactions and performs a rollback.

Note:-For example, a statement in BTEQ ends with a semicolon (;) as the last non-blank character in
the line. 
Thus, BTEQ sees the following example as two requests:
            sel * from table1;
            sel * from table2;
However, if you write these same statements in the following way, BTEQ sees them as only one request:
 sel * from table1
; sel * from table2;