ASSALAMUALAIKUM..

CHAPTER 7 : STORING ORGANIZATIONAL INFORMATION (DATABASE)

Learning outcomes

·         7.1 Define the fundamental concepts of the relational database model.

·         7.2 Evaluate the advantages of the relational database model.

·         7.3 Compare relational integrity constraints and business-critical integrity constraints.

·         7.4 Describe the benefits of a data-driven website.

·         7.5 Describe the two primary methods for integrating information across multiple databases.

                             Storing Organizational Information

Organizational information is stored in a database.

 

                                            Relational Database Fundamentals

A database maintains information about various types of objects (inventory), events (transactions), people (employees), and places (warehouses).

In a hierarchical database model, information is organized into a tree-like structure that allows repeating information using parent/child relationships in such a way that it cannot have too many relationships.

The network database model is a flexible way of representing objects and their relationships.

The relational database model is a type of database that stored information in the form of logically related two-dimensional tables.

 

ENTITIES AND ATTRIBUTES

An entity in the relational database model is a person , place, thing, transaction, or event about which information is stored.

 KEYS AND RELATIONSHIPS

A primary key is a field (or group of fields) that uniquely identifies a given entity in a table.

A foreign key in the relational database model is a primary key of one table that appears as an attribute in another table and acts to provide a logical relationship between the two tables.

 

                                 Relational Database Advantages

From a business perspective, database information offers many advantages, including:

·         Increased flexibility.

·         Increased scalability and performance.

·         Reduced information redundancy.

·         Increased information integrity (quality).

·         Increased information security.

INCREASED FLEXIBILITY

The physical view of information deals with the physical storage of information on a storage device such as a hard disk.

The logical view of information focuses on how users logically access information to meet their particular business needs.

           INCREASED SCALABILITY AND PERFORMANCE

Scalability refers to how well a system can adapt to increased demands.

Performance measures how quickly a system performs a certain process or transaction.

 

          REDUCED INFORMATION REDUNDANCY

Redundancy is the duplication of information, or storing the same information in multiple places.

 

          INCREASED INFORMATION INTEGRITY (QUALITY)

Information integrity is a measure of the quality of information.

Within a database environment, integrity constraints are rules that help ensure the quality of information.

There are two types of integrity constraints: (1) relational integrity constraints and (2) business-critical integrity constraints.

Relational integrity constraints are rules that enforce basic and fundamental information-based constraints.

Business-critical integrity constraints enforce business rules vital to an organization’s success and often require more insight and knowledge than relational integrity constraints.

 

          INCREASED INFORMATION SECURITY

Information is an organizational asset and must be protected.

Database offer several security features including :

• password - provides authentication of the user
• Access level - determines who has access to the different types of information.
• Access control - determine types of user access,such as read-only access.

 

                                   Database Management Systems

A database management system (DBMS) is software through which users and application programs interact with a database.

 

DATA-DRIVEN WEBSITES

A data-driven website is an interactive website kept constantly updated and relevant to the needs of its customers through the use of a database.

 DATA-DRIVEN BUSINESS INTELLIGENCE

Companies can gain business intelligence by viewing the data accessed and analyzed from their website.

 

                            Integrating Information among Multiple Databases

An integration allows separate systems to communicate directly with each other.

Without integrations, an organization will (1) spend considerable time entering the same information in multiple systems and (2) suffer from the low quality and inconsistency typically embedded in redundant information.

A forward integration takes information entered into a given system an sends it automatically to all downstream systems and processes.

A backward integration takes information entered into a given system and sends it automatically to all upstream systems and processes.