Why is there still a row limit in Microsoft Excel

Question

Until Office 2007, Excel has a maximum of 65,000 rows. Office 2007 bumped that up to a max of 1 million rows, which is nicer of course; but I'm curious -- why is there a limit at all? Obviously, performance will slow down exponetially as you increase the spreadsheet size; but it shouldn't be very hard to have Excel optimize for that by starting with a small sheet and dynamically "re-sizing" it only as needed. Given how much work it must have been to increase the limit from 65K to 1 million, why didn't they go all the way so it's limited only by the amount of available memory and disk space?

Answer 1

Because of optimizations, most likely. There are a total of 16 384 columns and 1 048 576 rows in Excel 2007. Weird figures? 20 bits = 1 048 576, 14 bits = 16 384
More than one 32-bit register can hold when 14 + 20 = 34 bits are added together.
However, they must also save the cell's format (text, number, etc.) and formatting (colors, borders etc). They use 34 bits for the cell number and 30 bits for other items if they use two 32-bit words (64 bit). What is the significance of this? They don't need to allocate all of the memory required for the entire spreadsheet in memory; instead, they just need to allocate the memory required for your data, and each piece of data is tagged with the cell it should be in.