A logical data type is a predefined set of characteristics for an attribute that specifies field length, default or user-defined name, and optional and required parameters. If your organization uses a logical model to define business rules for database development, you can add a logical data type and assign the data type to an attribute in the logical model. By assigning a logical data type to an attribute, you can create a standard, or template, for the representation of attribute data in all places in the logical model.
For example, a logical data type named DATE can have an internal format that includes month, day, year, hour, minute, and second (MM-DD-YYYY-HH-MI-SS). In the sample eMovies.erwin model (located in the \BackupFiles\Samples\Standard subdirectory where CA ERwin Data Modeler is installed), you can automatically store the date and time that a customer rents a particular movie in a single date column. You can format the date column on a customer movie rental report to show the date, the date and hour, the date, hour, and minute, or the date, hour, minute, and second for each customer rental.
You are provided a default list of logical data types. You can attach the default logical data types, and any data types that you add, to attributes.
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