Gregory Stark <stark(at)enterprisedb(dot)com> writes:
> That's just a special case of what would be expected to happen with memory
> allocation anyways though. Few allocators return memory to the OS anyways.
Well, that does happen on Linux for instance. Since Matt knew in his
original report that the xpath leak was intra-transaction, I assumed
he must be using a platform where malloc/free can release memory back
to the OS --- else he couldn't have seen that behavior from outside
the backend.
Still, it's entirely possible that some sort of high-water-mark is
involved somewhere, perhaps in malloc's internal data structures.
regards, tom lane