[Libreoffice] Calc need too much RAM to open large spreadsheets than Excel, fix?

[Michael Meeks]

Hi Sam,

On Wed, 2011-07-27 at 16:12 +0700, Samphan Raruenrom wrote:
> Last year I've done a comparison of memory usage on Windows between
> OpenOffice.org Calc 3.1 and MS Excel 2003/2007 for spreadsheets with
> simple formula of various size. I found that Calc take a lot more
> memory than Excel 2003/2007 when loading large spreadsheets.

	This is quite well known :-) thanks for the pretty graph though.
 
> Is there any work on LibreOffice to reduce memory usage of LibreOffice
> Calc on large spreadsheets?

	So - Kohei is working on 'ixion' - which attempts to thread
re-calculation, but IMHO -the- fundamental design problem with calc, is
something quite banal - the concept that a spreadsheet is built from
cells: without breaking that basic misconception I don't think we can do
any of the really interesting space / time optimisations we need to do.

	Having said that - the first trick with optimisation is profiling. Do
you have a memory profile ? until we have that it is impossible to see
what is chewing the memory - sadly, formulae are -very- large
storage-wise in calc [ cf. the above ], and are duplicated for every
cell. Even so, it'd be nice to run a memory profiler eg.

	http://projects.gnome.org/memprof/

	[ you will need to export G_SLICE=1 to get real results ]

	And see what is consuming the most memory, most likely one type will
dominate.

	Then we can help provide some pointers to improving that.

	How does that sound ?

	Thanks for the investigation ! :-)

	ATB,

		Michael.

-- 
 michael.meeks at novell.com  <><, Pseudo Engineer, itinerant idiot