To create a new type descriptor

1.	Select the Type Descriptors in the navigation bar to display a list of existing type descriptors.

2.	Select Add New in the navigation tab area.

The screen updates to display the type descriptor fields.

If the type descriptor will be used in a container component, check the Use for Container checkbox at the top of the screen.

The screen will refresh to show one additional field (Compression) in the Field Attributes area. In addition to the fields and checkboxes, a date field (TimeStamp) is automatically included in the type descriptor.

3.	In the Type Descriptor Name text box, enter the name.

4.	Define the Field Attributes for each field in the type descriptor. The Field Attributes describe the characteristics of a specific column in the type descriptor you are creating. The order of the field columns within the type descriptor is determined by the order in which you add fields.

a.	In the Field Name text box enter the field name.

b.	Select a Data Type from the drop-down list. The types are:

c.	If the field is defined as a String data type, enter the Size of the field.

d.	For a type descriptor that is used for a Container, select the Compression parameter.

Depending on the data type, you may see different options. The Compression types include:

Compression Parameter type	Description
Last	Enables you to explicitly add a value to a container that is being compressed. For example, if the container is compressed daily, and you want to hold the amount (compressed by Sum), count (compressed by Sum), and daily average (explicitly set by a Math expression), then use the Last operator when setting the compression behavior for the daily average field in the type descriptor.
Sum	When compression takes place, add together the values in this field. This option is available for data types of Int32, Double, DateTime.
Group By	When compression take place, use this field to group the same values together. This option is available for all data types.
Or	Available only for a Boolean data type, performs an or operation on the values in the field. True condition results when all the values in the field are true, or when there is a combination of true and false values. False condition results when all the values in the field are false
Blank	Not used in the compression. This option is a available for all data types

e.	Select a Field Type from the drop-down list. The options you see may depend on the other selections you have made. The types are:

As Attribute — This option is available for all data types; it is the most common setting. Use it for a field you might just want to look at. If this type descriptor is for container use, this is the only option you will see.

As Date — This option enables date data to be used for calculations.

As ID — While not typically used, this setting designates the field as a unique identifier for a join.

f.	Enter a Default Value for the field if one is required.

g.	Check the following checkboxes as applicable:

Allow NULL — when checked, the field can contain a NULL value.

Is Unique — when checked, the system will only insert the first, unique instance of the field into the container.

If the type descriptor is used on a container, then the field set as unique acts a type of unique key. If a new set of values is to be inserted into the container and the value for the unique field is the same as a value that is already in the container (in that field), then that entire row will not be inserted.

For example, it could be used to store the date of the first time a customer purchased some item.You could define a container with a date field and a product ID number, and set the product ID as a unique field. When a customer buys item 001, the ID 001 and the date of the purchase will be stored in the container. When the same customer buys item 001 again, the new date will not be inserted because 001 already exists in the container in the unique field.

h.	Check the appropriate radio button: Not Key or Primary Key.

These parameters are not offered when a type descriptor is used for a Container.

i.	Click the Add Fieldbutton on the right-hand side of the page.

As you add fields to the type descriptor, the editor displays their attributes in the lower portion of the screen.

5.	Continue defining and adding all the fields, as described above in step 4.

6.	Click Save Definition when complete. Or, if you want to delete all the fields you have been defining, click Clear Definition.