SELECT * FROM QSYS2.SYSTABLES
WHERE SYSTEM_TABLE_SCHEMA = 'MYLIB' and table_name = 'MYVIEW';
--returns 1 row

ALTER TABLE MYLIB.MYTABLE DROP COLUMN TEST2;

SELECT * FROM QSYS2.SYSTABLES
WHERE SYSTEM_TABLE_SCHEMA = 'MYLIB' and table_name = 'MYVIEW';
--returns 0 rows