Buffers to Nest Loop Join and him pages

Hi for all
Please,
I have two doubts. Can somebody help me please??
First doubt: I want know how many pages Postgres use when execute one query for Nest-loop-Join. I have used �explain analyze�, but it don�t give number of pages�
Second doubt: Normally when some SGBD exec the algorithm Nest-Loop Join, there are differences about the space of memory (buffer) for outer table and inner table. So, I want know where (What file?) Postgres define the number for this spaces (buffers) ? And can I change it?

I have asked for others forum, but anybody has asked me. So Please, SOMEBODY HELP ME !!!
By
Daniel

---------------------------------
Yahoo! doce lar. Fa�a do Yahoo! sua homepage.