THE PHYSICAL DESIGN
The Physical Design translates the Logical Design into physical terms.
Deliverables in this Stage will include a statement of requirements for the components and 
features in a Software Toolkit to implement the Logical Data Architecture. 
For example, one requirement is Enterprise Data Integration software.
The requirements will be formulated by identifying the generic components to be provided, 
and used as a checklist to evaluate potential 'make or buy' software solutions.
Some consideration will be given to operational aspects, such as Archiving, Database sizing 
and Backup and Recovery.
Data Access Requirements
The Data Architecture contains a number of Applications that share data.
The Requirements for data transformation between two Applications can be defined as the 
support of an interface mechanism between two indepedent Components which collaborate in sharing data.
Data Mapping is driven by Interface Schema which define the data to be sent and retrieved at each Interface.
Data Access Mechanisms include :-
1 Direct Access 
      - extract and return a file, provide SQL Access, either 'native' or using ODBC or JDBC
2 Through a published Data Service to get data
      - this would be a Method in O-O terminology, or a View in a Relational Database.
3 Through a published Business Rule or Service
      - this would be a Stored Procedure in a Relational Database.
4 Replicate onwards 
      - from a Source Application to local storage, where one of the above Access Mechanisms would then be used.
5 Real-time Feeds
      - such as News Feeds, appear in the Data Architecture for completeness, but they are not mapped to the Database 
        and are accessed by a technique that might be described as 'pass-through'.