Chapter 5: Data Resource Management

Character
The most basic logical data element that can be observed, a single alpha or numeric or other symbol, represented by one byte
Field
A grouping of related characters as a last name or a salary, represents an attribute of some entity General Purpose Application Programs – perform common information processing jobs for end users
Record
A grouping of attribute that describe an entity
File
A group of related records
Database
A collection of logically related data elements
Hierarchical Structure
Treelike structure of on-to-many parent-child relationships (each child can have only one parent)
Network Structure
Similar to hierarchical but allows many-to-many relationships (a child record can have more than one parent)
Relational Structure
The most widely used database model today; data is represented as a series of two-dimensional tables called Relations; each column is a named attribute of the entity, each row is an unnamed instance of that entity
Select
Create a subset that meets a criterion
Join
Temporarily combine two or more tables for comparison
Project
Create a subset of the columns in the temporary tables
Multidimensional Structure
Variation of the Relational model using multidimensional structures to organize and express relationships
Object-Oriented Structure
Combining the data of interest and the processes that act on that data into a structure called an object
Encapsulation
Allows complex data types
Inheritance
Allows replication of some/all of the characteristics of a parent object in the creation of a child object
Evaluation of Database Structures
Databases have grown more complex as needs have changed and grown in complexity
Data
An organizational resource that must be managed as any other resource
Operational Database
Store detailed data to support business processes and operations
Distributed Databases
Many organizations distribute their databases over multiple locations
Replication
Complex Process of updating distributed data
Duplication
Simplified method of updating distributed data
External Databases
Outside the firm, free or fee-based
Hypermedia Databases
Hyperlinked pages of multimedia
Data Warehouse
stores data extracted from other databases
Data Mart
Subset of a data warehouse focusing on a single topic, customer, product, etc.
Data Mining
Analyzing data warehouse to reveal hidden patterns and trends
Database Management Systems
A collection of programs to create, maintain, and use (retrieve) data in a database
Database Maintenance
Organizational databases need to be updated continually
Application Development
Facilitated by the Data Manipulation Language provided by the DBMS
External Databases
Outside the firm, free or fee-based
Object-Oriented Structure
combining the data of interest and the processes that act on that data into a structure called an object