對不起，看問題不仔細。

如果用澳土的database方法, 是不是可以enable session on web service. When the user type the first letter the web service starts to search words starting with that letter. It keeps search result, which should be much shorter than the total list, in session while returning the result to GUI. Then when longer segments arrive the search will only be from the memory, and every time the list to search from gets shorter.