CHAPTER 7: STORING ORGANIZATIONAL INFORMATION - DATABASES
Storing Organizational Information - Databases
Relational databases fundamentals:
- information is everywhere in an organization.
- information is stored in databases.
- Databases - maintains information about various types of objects (inventory), events (transactions), people (employees), and places (warehouses).
- database models include:
- Hierarchical database model - information is organizad into a tree-like structure (using parent/child relationships) in such a way that it cannot have too many relationships.
- Network database model - a flexible way of representing objects and their relationships.
- Relationship dataase model - stores information in the form of logically related two-dimensional tables.
Entities and Attributes:
- Entity - a person, place, thing, transaction, or event about which information is stored.
- Attributes (fields, columns) - characteristics or properties of an entity class.
Keys and Relationships:
Increased Flexibility:
- primary keys and foreign keys identify the various entity classes (tables) in the database
- Primary key - a field (or group of fields) that uniquely identifies a given entity in a table.
- Foreign key - a primary key of one table that appears an attribute in another table and acts to provide a logical relationship among the two tables.
- potential relationship database for Coca-Cola.
Relationship Database Advantages:
- database advantages from a business perspective include
- increased flexibility
- increased scalability and performance
- reduced information redundancy
- increased information integrity (quality)
- increased information security
Increased Flexibility:
- a well-designed database should:
- handle changes quickly and easily
- provide users with different views
- have only one physical view
- physical view - deals with the physical storage of information on a storage device eg hard disk.
- have multiple logical views
- logical view - focuses on how users logically access information.
- eg: a mail-order buss - 2 people view diff format (logical views) but same physical view.
Increased Scalability and Performance:
- a database must scale to meet increased demand, while maintaining acceptable performance levels
- 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:
- databases reduce information redundancy
- Redundancy - the duplication of information or storing the same information in multiple places.
- inconsistency is one of the primary problem with redundant information-difficult to decide which is most current and most accurate.
Increase Information Integrity (Quality):
- Information integrity - measures the quality of information.
- Integrity constraint - rules that help ensure the quality of information
- Relationship integrity constraint - rule that enforces basic and fundamental information-based constraints
- eg. users cannot create an order for a nonexistent customer, provide a markup percentage that was negative etc.
- Business - critical integrity constraint - rule that enforce business rules vital to an organization's success and often require more insight and knowledge than relational integrity constraints
- eg. product returns are not accepted for fresh product 15days after purchase.
Increased Information Security:
- information is an organizational asset and must be protected
- databases 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 - determines types of user access, such as read-only access
Database Management Systems:
- database management systems (DBMS) - software through which users and application programs interact with a database.
DATA-DRIVEN WEB SITES
- data-driven web sites - an interactive Web site kept constantly updated and relevant to the needs of its customers through the use of a database.
Data-Driven Web Site Business Advantages:
- Development
- Content management
- Future expandability
- Minimizing human error
- Cutting production and update costs
- More efficient
Data-Driven Business Intelligence:
- BI in data-driven Web site
Integrating Information among Multiple Databases:
- Integration - allows separate systems to communicate directly with each other
- Forward integration - tkes information entered into a given system and sends it automatically to all downstream systems and processes
- Backward integration - takes information entered into a given system and sends it automatically to all upstream systems and processes.
2 NOVEMBER 2017
THURSDAY
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