Excel 2007 Files Are WinZip/WinRAR Files In Disguise

I am not going to say anything about the ribbon or the diamond, this not a post about that. Create a new file in Excel 2007 with 250000 (that is a quarter million) rows. Just have 1 column with numbers from 1 to 250000. Save the file but keep it open. I applied a currency format to mine, see pic below.




Just for fun save it also in Excel 2003 format, you will get a warning and the file will only contain 65536 rows. I also captured that as a screenshot, the pic is below.




Now look at the files, do you see that the Excel 2003 file is bigger in size than the Excel 2007 file even though it has only one fourth the rows. Now locate the file and rename the xlsx extension of the Excel 2007 file to rar or zip. That is right the file is compressed, open the file up with WinZip or WinRAR. Open the Worksheets folder inside the xl folder, you will see a worksheet there which is about 17MB unpacked and about 2 MB packed. The pic of the RAR file is below.



Interesting stuff right?


Cross-posted from SQLBlog! - http://www.sqlblog.com/