Append data to existing hdfs directory


Hi there - I am using sqlcontext to retrive the data from hive table and I am trying to append the data to existing folder.
When I am doing this, I am getting the error that the folder already exists.
“Output directory hdfs:// already exists”

My question here is how can I insert the data to existing directory, because in real world scenario, we cannot create the folder everytime we process the data.