The following lines contain the word 'select', 'insert', 'update' or 'delete':
UPDATE MTL_TRANSACTIONS_INTERFACE
SET LOCK_FLAG = 1
WHERE PROCESS_FLAG = 1
AND TRANSACTION_HEADER_ID = l_transaction_header_id;
select error_code, error_explanation
into p_error_code, p_error_explanation
from mtl_transactions_interface
where transaction_header_id = l_transaction_header_id
and rownum = 1;