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Define Teradata Database Column Properties

In a model based on a Teradata target server, you use the two Teradata tabs in the Columns dialog or the Domain Dictionary dialog to manage the datatype, null option, default value, and other properties for the selected column.

Note: An asterisk next to any property indicates that the property value is derived from domain inheritance or a macro.

To define Teradata column properties

1. Click Columns on the Model menu.

   The Columns dialog opens.

2. Select from the following options on the Teradata tabs, and click OK:

   (First Teradata tab)

   Teradata Datatype

   Lets you select a datatype from the list to change the datatype of the selected column. If the selected datatype requires a value for precision, scale, or both, enter the value inside the datatype parentheses. For example, you can select the DECIMAL() datatype and specify a precision of 2 and a scale of 10 inside the parentheses, to assign the datatype DECIMAL(2,10) to the selected column.

   Null Option

   Specify a null option for the selected column.

   Average Width

   Enter an estimated average width for the column if the option is available (not dimmed). You can later use the Volumetrics dialog to calculate table and database size estimates based on these and other values.

   Percent NULL

   Enter the estimated percentage of nulls used for that column if the option is available. For example, you can estimate a variable width ADDRESS 2 column assigned a width of 50 characters, to be NULL about 30 percent of the time. Use whole numbers. You can later use the Volumetrics dialog to calculate table and database size estimates based on these and other values.

   (Second Teradata tab)

   COMPRESS

   Select this option to reduce the amount of physical storage space occupied by a column that contains a large number of nulls, zeros, blanks, or the specified constant. Enter the constant you want to compress in the text box opposite the COMPRESS check box. You cannot compress columns that are components of a primary index.

   Format

   Lets you assign a display format. The display format controls how data appears in Teradata applications. For example, dd-mmm-yy displays a date value as 01-May-07. For CHAR(n) datatypes, if you do not specify a format, the format is automatically generated as X(n), where n is the number of characters defined in the datatype. Click the button to open the Display Formats dialog.

   Title

   Lets you enter a name (up to 60 characters) that identifies the column values in Teradata applications. By default, the column name with a colon appended is inserted (for example, customer_name:).

   CASE

   Select this check box to specify whether column values should be stored exactly as entered or be automatically converted to uppercase characters. This check box appears only if the datatype for the selected column is CHAR, VARCHAR(n), or LONG VARCHAR. Select Casespecific to store the value for a column exactly as it is entered, or select Uppercase to store the value for a column in uppercase.

   Character Set

   Lets you define a character set.

   Teradata column properties are defined and the Columns dialog closes.