Query size?

I'm working with another developer to produce an iPhone app - he's writing the 
app and I'm writing the server that provides the data to it.  One of the 
queries he's doing might produce hundreds or thousands of results, and he 
doesn't want me sending that much data.

So I'm wondering if there is a simple way to determine if a query is going to 
produce a result of more than N rows?  Is the only way to do a "select 
count(*)" query first, or there something in the ResultSet that tells me how 
many results are queued up?

-- 
Paul Tomblin  http://blog.xcski.com/
God is real, unless declared as an integer.