Rather than locking a table (very unusual in Oracle), you can try simply misspelling a column name in your SQL statement. Oracle's compiler will throw an error for that. 
select fred from global_name
       *
ERROR at line 1:
ORA-00904: "FRED": invalid identifier

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In reply to Re^2: Throw DB error by Anonymous Monk
in thread Throw DB error by Bheema_Tyco

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