Improve function performance (it is urgent please help me regarding)

Question

i write nearly ten database function many of them are interlinked with each other when i call these function from a report then report become slower down too much nearly halted situation for 15 minutes
my question is that how i can improve the performance of these function by any method
note that these function just using one or two cursor and eache curosor containing nearly 100 records

Answer 1

Also: nearly ten functions (nine and a half? nine and seven-eigthts?) is a lot of functions to fix all at once.
1) Start with just one function. Get it working fast enough using the techniques Kamal mentions in standalone.
2) Tune all the functions independently.
3) Then add two functions together and see how they work. Tune when necessary.
4) Continue adding one function to the report and tune the ensemble until finished.
Good luck, APC