Schema DDL Defining an item
U929-J-Z125-9-76 55
Dokuschablonen 19x24 Version 7.3us für FrameMaker V7.x vom 14.02.2007 © cognitas GmbH 2001-2007 24. Oktober 2007 Stand 09:30.23 Pfad: G:\vogt\fsc\ud s\Manuale\en\udsent_e\uds ent.k04
4.2 Defining an item An “item” is the smallest unit of data within a record type th at can be assigned a name by
means of the schema DDL. “Item” also stands for all the values which can b e assumed by
the item. The particular value contained in an item is referred to as item content. The
entirety of all possible item contents is known as the value range of the item.
Defining an item basically means defining an item’s value range. The item descr iption also
determines the physical form of storage of an item content.
Figure 9: Item types
figure 9 shows the various possibilities of physical storage for the con tents of an item.
DATABASE-KEY-LONG
item
numeric
alphanumeric
database key
un-
packed packed binary DATABASE-KEY
fixed length variable length
national