I think the variable rownum could be used for this too, if your database supports it. Basically every result returned is assigned a rownum and you can can use it like:

select * from sometable where rownum < 10;
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This should select only the first 10 (subject to an off-by-one error, as I don't know if rownum starts at 0 or 1) records that would have been returned by this query.

Of course, simply using the cursor and ending the query after retreiving the first 10 results will also work, as would limit if your system supported it. By using limit or rownum you can still use the very handy selectall_* routines, though.