[Monetdb-developers] [Monetdb-checkins] MonetDB/src/gdk gdk.mx, , 1.278, 1.279 gdk_bat.mx, , 1.213, 1.214 gdk_posix.mx, , 1.168, 1.169 gdk_relop.mx, , 1.161, 1.162 gdk_utils.mx, , 1.241, 1.242

Martin Kersten Martin.Kersten at cwi.nl
Fri Apr 3 12:41:45 CEST 2009

Peter Boncz wrote:
> Update of /cvsroot/monetdb/MonetDB/src/gdk
> In directory 23jxhf1.ch3.sourceforge.com:/tmp/cvs-serv31767/gdk
> Modified Files:
> 	gdk.mx gdk_bat.mx gdk_posix.mx gdk_relop.mx gdk_utils.mx 
> Log Message:
> various tweaks to the memory mangement
> - tune the GDK_mmap_minsize to vary between full RAM size and 128MB
>   (lowest when memory pressure is extreme)
> - in fetchjoin, when the optimization of string heap copying is applied
>   (instead of creating a new string heap and inserting into it), try
>   to share the heaps in virtual memory (rather than copying it)
>   This is possible with the logical view mechanism.
>   now fetchjoin, batcopy and remap use this VM heap sharing.
If we do a fetchjoin(L,R) to a table R that does not fit in memory,
and the operand L has more oids then the number of pages in R
then we should also sort L on the tail oids first

This under the constraint that sorting L also cost some IO

If you are tweaking in that area anyway, such a patch is
> - disable vmalloc on Linux -- well actually on platforms
>   that do not have posix_fadvise. A bit of a hack.

More information about the developers-list mailing list