--------------------------------------------------
ALTER TABLE <schema>.<table_name> SET UNUSED COLUMN <column_name>;
ALTER TABLE <schema>.<table_name> DROP UNUSED COLUMNS;
Reference:
39726, 00000, "unsupported add/drop column operation on compressed tables"
// *Cause: An unsupported add/drop column operation for compressed table
// was attemped.
// *Action: When adding a column, do not specify a default value.
// DROP column is only supported in the form of SET UNUSED column
// (meta-data drop column).
