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Schema DDL Defining an item
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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\uds\Manuale\en\udsent_e\udsent.k04
4.2 Defining an item
An “item” is the smallest unit of data within a record type that can be assigned a name by
means of the schema DDL. “Item” also stands for all the values which can be 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 description 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 contents of an item.
DATABASE-KEY-LONG
item
numeric
alphanumeric
database key
un-
packed
packed binary
DATABASE-KEY
fixed length variable length
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