ALTER TABLE Failed [9478] Table must be column partitioned - forum topic by Sway1532

Hello everyone, I am trying to change the datatype of a column.
My statment: 

ALTER TABLE DWBATCHDEV.DBQLSTEPTBL_HST

ADD COLUMN  (StepStartTime TIMESTAMP(6) FORMAT 'YYYY-MM-DDBHH:MI:SS.S(F)Z');

Not sure how teradata works when it comes to chagning the datatype, but I get the error "ALTER TABLE Failed [9478] Table must be column partitioned "

I am going to create a new table.