Include all functions and performance

Dear List, I have a library of functions which I was thinking of including all from one file, in a kind of heirarchy. That way I can just include the one file in each php page and have all the functions available to me. (a kind of lazy approach I know) What I was wondering, if using the apache server, will this kind of approach affect the performance of my pages, since obviously all functions won't be used for every page (perhaps just a couple). I know from Java that only the functions that are used in the code are included when compiling, but with php there's no compilation (i think). Good, bad or ugly? Thanks Terence