Couple of questions about menus and database

Hi, I just have a couple of questions out of curiosity

1) it says in the codex that add_menu_page() returns a string that can be used as a page hook, is there a way to get that page hook value after add_menu_page() has already be called? I can’t find any get functions in the codex though.

2) Does dbDelta(‘query’); check if the database table already exists before running the query or do I have to run a query to check if table exists? I’m just trying to reduce any redundancies in my code.

Thanks
-Charles