questions about wm trigger

hello ,all.
I have several questions about wm trigger. We are using wm trigger to accept the documents sent from GXS enterprise with the enterprise adapter.
1 Is there any way that wm will store the received file on disk? Since i just found out there are some ‘TriggerStoredata0000000’ like file in DocumentStore folder. But i can’t read it. Am i supposed to read the trigger stored file? And how can i read it since i do wanna know exactly the processed file if an error occured.
2 could i clear the trigger document queue manually? When the servive called by trigger crashed, there are other documents waiting in the queue. If the queue is not cleared, after the server restart, all these waiting document will be processed, is that right?
Any suggentions are higtly appreciated!