Changing a Column Data Type

In general, the following requirements apply to changing a column's data type:

• The change must not require storage reorganization. After you modify a column's data type, data that you load conforms to the new definition.

• The column must not be referenced in the segmentation expression of any table projection.

• You can change the width of columns within the same class of data type. Vertica supports reducing column widths within the data type class if the following conditions are true:

  • Existing column data is no greater than the new width.
  • All nodes in the database cluster are up.