As well as UDFs, you can also incorporate SPs in where clauses, and
this might require full evaluation.

For example

SELECT T.FLD1,T.FLD2... FROM TABLE1 T
WHERE T.FLD3 = X AND
((SELECT SP.UPDATE_RESULT FROM MY_UPDATE_PROC SP) = 'OK')

It might not be elegant, and it might make me blush, but it works.