:: Select xxxx from yyyy
:: Union
:: Select wwww from zzzz
::
:: I presume that it is what you meant because there is no
:: point otherwise. Both sections of the query can be optimised
:: separately, so it should be fine.

Yes, different tables. Sorry. :)

:: would be a bad idea if there is no index on Name.

Yes. I was just curious if running the two as a union, vs running them
separately and tallying details in the client will cause any optimization or
other problems.