+ eCheckExist, /* look up the item, return the timestamp if its there, 0 if not. */
+ eCheckUpdate, /* if it exists, refresh in db timestamp. return the timstamp if its there, 0 if not. */
+ eUpdate, /* insert/update the new value, return the old if its there, 0 if not. */
+ eWrite /* write this to DB, unconditional. */