Hello,<br><br>I have been working a bit on performance related calc problems for 3.5. <br><br>I have at least one item left for 3.5: for nearly every undo step we create a full copy of the whole document. For 3.5 I planned to improve the undo code for sheets that means that we no longer copy every sheet to an undo document which is insane. If I have a good idea i might as well have a look at the undo code for a single sheet. I hope that there is a better solution than to copy the whole content of a sheet to a new sheet.<br> <br>Then we have of course a little problem with columns. We create for every sheet 1024 ScColumns and ScAttrArray even if we don't need them which needs some memory. I think I did some profiling and a single sheet needs about 150kB on a 64bit computer.<br> <br>These are at least two problems I know, but we have for sure several other problems too.<br><br>Regards,<br>Markus<br><br><div class="gmail_quote">2011/7/27 Kevin Hunter <span dir="ltr"><<a href="mailto:hunteke@earlham.edu">hunteke@earlham.edu</a>></span><br> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div class="im">At 6:07am -0400 Wed, 27 Jul 2011, Michael Meeks wrote:<br> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="im"> On Wed, 2011-07-27 at 16:12 +0700, Samphan Raruenrom wrote:<br> </div><div class="im"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> Is there any work on LibreOffice to reduce memory usage of<br> LibreOffice Calc on large spreadsheets?<br> </blockquote> <br></div><div class="im"> but IMHO -the- fundamental design problem with calc, is something<br> quite banal - the concept that a spreadsheet is built from cells:<br> without breaking that basic misconception I don't think we can do<br> any of the really interesting space / time optimisations we need to<br> do.<br> </div></blockquote> <br> Can you elaborate a little on this fundamental design flaw? As a naive and unfortunately focused elsewhere personality, I don't immediately know of a better model for creating a spreadsheet. Is it "just" a problem of sparsity? Or is there a much more sophisticated method for memory sharing of various similar cell attributes, perhaps analogous to CSS?<br> <br> Thanks,<br><font color="#888888"> <br> Kevin</font><div><div></div><div class="h5"><br> ______________________________<u></u>_________________<br> LibreOffice mailing list<br> <a href="mailto:LibreOffice@lists.freedesktop.org" target="_blank">LibreOffice@lists.freedesktop.<u></u>org</a><br> <a href="http://lists.freedesktop.org/mailman/listinfo/libreoffice" target="_blank">http://lists.freedesktop.org/<u></u>mailman/listinfo/libreoffice</a><br> </div></div></blockquote></div><br>