Re: Releasing memory during External sorting?

> On most platforms it's quite unlikely that any memory would
> actually get
> released back to the OS before transaction end, because the memory
> blocks belonging to the tuplesort context will be intermixed with
> blocks
> belonging to other contexts. So I think this is pretty pointless.
> (If you can't afford to have the sort using all of sort_mem, you've
> set
> sort_mem too large, anyway.)
On OpenBSD 3.8 malloc use mmap(2) and no more sbrk.
So, as soon as the bloc is free, it returns to the OS.
Access to the freed pointer crashs immediatly.

Cordialement,
Jean-Gérard Pailloncy