Everything leaks; How it mm suppose to work?

Hi,

I added these lines to tcop/postgres.c just before the ReadCommand call
(which is in an infinite loop).

+ 		printf("Allocount: %ld; FreeCount: %ld; Diff:%ld\n", 
+ 				getPAllocCount(),
+ 				getPFreeCount(),
+ 				getPAllocCount() - getPFreeCount());
+ 

And the following lines to mmgr/palloc.c
  
+ static long pallocCount = 0;
+ static long pfreeCount = 0;
+ 
+ long getPAllocCount()
+ {
+ 	return pallocCount;
+ }
+ 
+ long getPFreeCount()
+ {
+ 	return pfreeCount;
+ }

  void *
  palloc(Size size)
  {
+ 	pallocCount++;
   ...

  void
  pfree(void *pointer)
  {
+ 	pfreeCount++;
        ...

Running postgresql in interactive mode shows that for each query I 
type there is memory lost. The exact amount of memory lost depends on
the query I use. The amount of memory not freed is also a function
of the number of tuples returned.

Now I'm hoping there is an easy way to find out about how this is _supposed_ 
to work. Any one feel like giving a nice little explanation?

Thanks, with regards from Maurice.