If you write new data with a key that is already present, the existing columns are overwritten or new columns are added. There is no way to cause a duplicate key to be inserted.
On Wed, Jul 28, 2010 at 6:16 PM, Rana Aich <aichr...@gmail.com> wrote: > Hello, > I was wondering what may the pitfalls in Cassandra when the Key value is not > UNIQUE? > Will it affect the range query performance? > Thanks and regards, > raich > >