Computer Software & Data Storage Concepts

Network Architecture

This is the Network Architecture DFD that allocates processors and computer device to the network server and ensures the connectivity between the PC clients and the web servers and the interaction with the application servers.

Data Distribution and Technology Assignments

The Database consisting tables in the sql server database is named and added to the physical DFD and they are connected to the appropriate application server for processing.

Process distribution and Technology Assignments

The DFD event for each process of the physical and logic event diagrams are assigned to the web client. Business logic is assigned to application servers and data capture and editing are assigned to the computer users. Product distribution (or place) is one of the four elements of the marketing mix. Distribution is the process of making a product or service available for use or consumption by a consumer or business user, using direct means, or using indirect means with intermediaries. Distributed processing is a phrase used to refer to a variety of computer systems that use more than one computer (or processor) to run an application. This includes parallel processing in which a single computer uses more than one CPU to execute programs.

More often, however, distributed processing refers to local-area networks (LANs) designed so that a single program can run simultaneously at various sites. Most distributed processing systems contain sophisticated software that detects idle CPUs on the network and parcels out programs to utilize them. Another form of distributed processing involves distributed databases. This is databases in which the data is stored across two or more computer systems. The database system keeps track of where the data is so that the distributed nature of the database is not apparent to users.

Person/Machine boundaries

The region processing the logical and data manipulation are the machine boundary and the person interaction with the GUI is the person boundary.

Key-Based (KB) Model is a data model that fully describes all of the major data structures that support a wide business area. The goal of a KB model is to include all entities and attributes that are of interest to the business. As its name suggests, a KB model also includes keys. In a logical model, a key identifies unique instances within an entity. When implemented in a physical model, a key provides easy access to the underlying data. Basically, the key-based model covers the same scope as the Entity Relationship Diagram (ERD) but exposes more of the detail, including the context where detailed implementation level models can be constructed.

A unique key or primary key is a key that uniquely defines the characteristics of each row. The primary key has to consist of characteristics that cannot collectively be duplicated by any other row. In an entity relationship diagram of a data model, one or more unique keys may be declared for each data entity. Each unique key is composed from one or more data attributes of that data entity. The set of unique keys declared for a data entity is often referred to as the candidate keys for that data entity. From the set of candidate keys, a single unique key is selected and declared the primary key for that data entity.

In an entity relationship diagram, each entity relationship uses a unique key, most often the primary key, of one data entity and copies the unique key data attributes to another data entity to which it relates. This inheritance of the unique key data attributes is referred to as a foreign key and is used to provide data access paths between data entities. Once the data model is instantiated into a database, each data entity usually becomes a database table, unique keys become unique indexes associated with their assigned database tables, and entity relationships become foreign key constraints. In integrated data models, do not become foreign key constraints since commonality relationships are a peer-to-peer type of relationship.

Database System

Database management system (DBMS) is the software that allows a computer to perform database functions of storing, retrieving, adding, deleting and modifying data. Relational database management systems (RDBMS) implement the relational model of tables and relationships. The Data store software for the web application is the SQL Server software. SQL Server is a software library that implements a self-contained transactional SQL database engine. SQL Server is the most widely deployed database engine in the world.