plperlu and 'use' statement scope question

Hello list,

I'm designing a plperlu function and i was wondering about scoping on
use statements for external libraries.  I couldn't find any information
on it in the documentation or in the mail archives, so any information
would be much appreciated.

The function is intended to be used as part of a select statement:

select foo,my_function(bar) as baz from table where baz > some_value
order by baz

And the function uses an external module to do much of the heavy
lifting.  What I'm wondering is will the function have to reload the
external module for every row, or is plperlu smart enough to only load
it once for the entire query?  In the other extreme, I'm hoping that it
does reload the external module for each query, as I expect to be
dynamically rewriting one of the modules that that external module requires.

-Stephen