I have a Time Series Data that I want to persist in Cassandra database.

Example Sheet : Here t1, t2, t3 are my time series values while a,b,c,d,e,f are my hierarchies.

Composite_column Value
a:b:c:t1 v1
a:b:c:t2 v4
a:b:d:t2 v2
a:e:f:t3 v3

Now, for each row I want to create a composite column for the rows under the field Composite_column and add to it the value under the field Value. The default action of cassandra output transformation in Pentaho only allows for creation of 3 separate rows with keys in the field Composite_column and values in the field Value. How do I get the cassandra output step to perform the desired behavior ie. persisting all these entries in a single row of cassandra database?