Physical Schema

SV-11

Product Definition. The Physical Schema product is one of the architecture products closest to actual system design in the Framework. The product defines the structure of the various kinds of system data that are utilized by the systems in the architecture. Product Purpose. The product serves several purposes, including (a) providing as much detail as possible on the system data elements exchanged between systems, thus reducing the risk of interoperability errors, and (b) providing system data structures for use in the system design process, if necessary.

Product Detailed Description. SV-11 is an implementation-oriented data model that is used in the Systems View to describe how the information requirements represented in Logical Data Model (OV-7) are actually implemented. Entities represent (a) system data flows in SV-4, (b) system data elements specified in SV-6, (c) triggering events in SV-10b, and/or (d) events in SV-10c.

There should be a mapping from a given OV-7 to SV-11 if both models are used. The form of SV-11 can vary greatly, as shown in Figure 5-40. For some purposes, an entityrelationship style diagram of the physical database design will suffice. References to message format standards (which identify message types and options to be used) may suffice for messageoriented implementations. Descriptions of file formats may be used when file passing is the mode used to exchange information. A Data Definition Language (DDL) (e.g., Structured Query Language [SQL]) may also be used in the cases where shared databases are used to integrate systems. Interoperating systems may use a variety of techniques to exchange system data and have several distinct partitions in their SV-11 with each partition using a different form. Standards associated with entities (e.g., entities are those defined in DoD XML Registry) are also documented in this product.