Robert Haas <robertmh...@gmail.com> writes: > On Mon, Apr 11, 2011 at 3:11 PM, A.M. <age...@themactionfaction.com> wrote: >> What do you mean by "leakier"? The goal here is to extinguish SysV shared >> memory for portability and convenience benefits. The mini-SysV proposal was >> implemented and shot down by Tom Lane.
> I mean I'm not convinced that fcntl() locking will be as reliable. I'm not either. Particularly not on NFS. (Although on NFS you have other issues to worry about too, like postmasters on different machines being able to reach the same data directory. I wonder if we should do both SysV and fcntl locking ...) > I know Tom shot that down before, but I still think it's probably the > best way forward. Did I? I think I pointed out that there's zero gain in portability as long as we still depend on SysV shmem to work. However, if you're doing it for other reasons than portability, it might make sense anyway. The question is whether there are adequate other reasons. > The advantage I see is that we would be able to > more easily allocate larger chunks of shared memory with changing > kernel parameters, Yes, getting out from under the SHMMAX bugaboo would be awfully nice. > and perhaps even to dynamically resize shared memory chunks. This I don't really believe will ever work reliably, especially not in 32-bit machines. Whatever your kernel API is, you still have the problem of finding address space contiguous to what you were already using. regards, tom lane -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers