Calc/hacks/number of rows
Now and then people ask whether increasing the row limit above 64k lines or the column limit above 256 columns for OpenOffice.org version 2.4 or 1024 columns for 3.0 would be possible.
Well, it depends on what your goal is. For personal use you may set
MAXROWCOUNT_DEFINE in sc/inc/address.hxx to
a different value, multiple of 128, and recompile the application respectively the libsc680*.so and shove it under your existing installation. However, doing so implies that you don't save to any binary file format like Excel or whatsoever, otherwise you risk loss of data. You'll also encounter drawing layer misfits in higher row numbers, may experience performance problems, and there may be other quirks lurking. Note that it generally works for data and formulas, but otherwise is completely untested.
For the number of columns the same applies to the
MAXCOLCOUNT_DEFINE in sc/inc/address.hxx, just that the value must be a multiple of 16 instead.
A successful proof of concept was done by Laurent Godard, using 2000000 rows and 32000 columns, resulting in the lower right corner cell address AUHT2000000 ... see http://blogs.nuxeo.com/sections/blogs/laurent_godard/2006_02_08_the-spreadsheet-next
Please note again that this is a hack and while it may serve you doing some data crunching bear in mind that exchanging documents with other releases or applications will not work.
However, we should implement this expansion properly, also to be able to handle larger spreadsheet documents created with other applications. There are RFEs for this, http://qa.openoffice.org/issues/show_bug.cgi?id=30215 for number of rows and http://qa.openoffice.org/issues/show_bug.cgi?id=31612 for number of columns.