When I run the drop database command within impala it doesn't remove the corresponding HDFS files.
 
               drop database if exists databasename cascade;
 
I want to drop a database and remove the corresponding hdfs files.
 
Per the documentaion - 
DROP DATABASE Statement
Removes a database from the system.
The physical operations involve removing the metadata for the database from the metastore, and deleting the corresponding *.db directory from HDFS.
 
The cascade parameter drops the tables within the database first.
 
I'm running CDH 513.3 and CM 514.3.