It depends a little on your write pattern: - Wide rows tend to get distributed over more sstables so more disk reads are necessary. This will become noticeable when you have high io load and reads actually hit the discs. - If you delete a lot slice query performance might suffer: extreme example: create 2M cols, delete the first 1M and then ask for the first 10.
On Feb 7, 2011, at 7:07 AM, Aditya Narayan wrote: > Does huge variation in no. of columns in rows, over the column family > has *any* impact on the performance ? > > Can I have like just 100 columns in some rows and like hundred > thousands of columns in another set of rows, without any downsides ?