code: private void alterColumn(AlterTableOptions alterTableOptions, Schema schema, ColumnInfo columnInfo,
              AtomicBoolean updated)
      {
          if (!KuduDBDataHandler.hasColumn(schema, columnInfo.getColumnName()))
          {
              // add if column is not in schema
              alterTableOptions.addNullableColumn(columnInfo.getColumnName(),
                      KuduDBValidationClassMapper.getValidTypeForClass(columnInfo.getType()));
              updated.set(true);
          }
          else
          {
              // check for type, drop and add if not consistent TODO: throw
              // exception or override?
              if (!schema.getColumn(columnInfo.getColumnName()).getType()
                      .equals(KuduDBValidationClassMapper.getValidTypeForClass(columnInfo.getType())))
              {
                  alterTableOptions.dropColumn(columnInfo.getColumnName());
                  alterTableOptions.addNullableColumn(columnInfo.getColumnName(),
                          KuduDBValidationClassMapper.getValidTypeForClass(columnInfo.getType()));
                  updated.set(true);
              }
          }
      }
docs: Alter column.
  
  @param alterTableOptions
  the alter table options
  @param schema
  the schema
  @param columnInfo
  the column info
  @param updated
  the updated