Question

Is there a performance difference between using mysql_result and mysql_array_assoc to loop through a large SQL select result?

Answer 1

From the mysql_result() manual page:

When working on large result sets, you
should consider using one of the
functions that fetch an entire row
(specified below). As these functions
return the contents of multiple cells
in one function call, they’re MUCH
quicker than mysql_result(). Also,
note that specifying a numeric offset
for the field argument is much quicker
than specifying a fieldname or
tablename.fieldname argument.

So it seems that mysql_array_assoc(), one of the functions that quote refers to, is going to be your best bet.