If I may add, that is indeed the default behaviour of the kernel, which can be disabled with

vm.overcommit_memory = 2 
in /etc/sysctl.conf

Perhaps MonetDB could check this system setting and decide on which strategy to use?

On 20 September 2016 at 18:24, Sjoerd Mullender <sjoerd@acm.org> wrote:
As far as I understand it, malloc on Linux will happily succeed even if
there is not enough memory+swap to hold all data.  So you can't rely on
malloc failures to tell you to switch to mmap.

On 09/20/2016 06:19 PM, Hannes Mühleisen wrote:
> Hello list,
>
> we were wondering about the purpose of GDK_mmap_minsize when creating transient columns. The attached patch will always *try* to malloc/realloc a transient column but still fall back to memory-mapped files if malloc should fail. This dramatically improves performance. Any good reason why this should not be the default behaviour?
>
> Thanks,
>
> Mark and Hannes
>
>
>

--
Sjoerd Mullender



--
Sjoerd Mullender


_______________________________________________
developers-list mailing list
developers-list@monetdb.org
https://www.monetdb.org/mailman/listinfo/developers-list