Simon Riggs <simon@2ndquadrant.com> writes:
> I still do, for multi-user systems. Releasing unused memory from a large
> CREATE INDEX will allow that memory to be swapped out, even if the brk
> point can't be changed.
Say what? It can get "swapped out" anyway, whether we free() it or not.
More to the point, though: I don't believe that the proposed patch is a
good idea --- it does not reduce the peak sortmem use, which I think is
the critical factor for a multiuser system, and what it does do is
reduce the locality of access to the sort temp file during the merge
phases. That will definitely have some impact; maybe small, but some;
and I don't see where the benefit comes in.
regards, tom lane
