Tunning PostgreSQL performance for views on Windows

Hello,

I'm developing a BI and as database it's using postgresql 8.2, how data
are very detailed, I'm creating a view to consolidate the most important
data, but the performance of view is very poor, 1 minute to perform more
or less without where clause.
I need to know how I can increase the performance, if exist some option
to do cache, because the view will change only one time per day.
My configuration is default, without modifications after install.
I'm using windows 2003 server with a dell server with 4GB of memory.

To create the view, I created some functions, and then perform they on
one select like:
select A.field1, B.field2, ... from function_A() A, function_B() B...
Is this the best way to do it?

I appreciate any help.

Thanks