The column name.

The data type for the data in each column. You can select one of the following data types:

bigint
datetime
decimal
integer
string

The precision for each column. Precision is the maximum number of digits or the maximum number of characters that the column can accommodate.

The precision values you configure depend on the data type.

The scale for each column. Scale is the maximum number of digits that a column can accommodate to the right of the decimal point. Applies to decimal columns.

The scale values you configure depend on the data type.

An optional description for each column.

Indicates if the column can contain null values.

Identifies a primary key column in a table that you import from a database source.

If you update an unmanaged reference table, you cannot add duplicate values to a column that originates from a primary key column in the source database. You can add duplicate values to any column in a managed reference table.