Is it possible to add a column to a partition in a partitioned table?

I have a large partitioned table of 16 billion plus records. I am currently updating one of the columns to NULL using the partition number. The process is cumbersome in that it takes a lot of time to complete the operation. One of the partitions of 70 GB took 11 hours to complete the update. So my question is, is it possible to create a column within a partition so that I can use it to do the update in a faster way? Ideally I'd like to create the new column with NULL values, then delete the old column and rename the new one to the same name, rather than update billions of rows i.e. create NewColumn with null values rename CurrentColumn to CurrentColumn_delete rename NewColumn to CurrentColumn Delete CurrentColumn_delete but only on the partition and not whole table