title: kdb dbmaint to backfill data with existing data
body: <p>I would like to use dbmaint package to add a column to all dates in hdb, and then backfill the column I add with the data from another existing column in the same table to all dates.</p>
  
  <p>I just added a column to all dates with default value. How can I backfill the column with the data from another column? I am not sure how this can be achieved. </p>