Database Design Chapter 1

Ad hoc query

A "spur-of-the-moment" question.

Data Dictionary

A DBMS component that stores metadata—data about data. The data dictionary contains data definitions as well as data characteristics and relationships. May also include data that is external to the DBMS.

Desktop database

A Single-User database that runs on a PC

Field

A character or group of characters (alphabetic or numeric) that has a specific meaning. A field is used to define and store data.

Database Management System (DBMS)

A collection of programs that manages database structure and controls access to the data stored in the database.

File

A collection of related records. For example, a file might contain data about the students currently enrolled at Gigantic University.

Data anomaly

A data abnormality in which inconsistent changes have been made to a database. For example, an employee moves, but the address change is not corrected in all files in the database.

XML database

A database system that stores and manages semi-structured XML data

Record

A logically connected set of one or more fields that describes a person, place, or thing. For example, the fields that constitute a record for a customer might consist of the customer's name, address, phone number, date of birth, credit limit, and unpaid balance.

Extensible Markup Language (XML)

A metalanguage used to represent and manipulate data elements. Unlike other markup languages, XML permits the manipulation of a document's data elements.

Workgroup database

A multi-user database that supports a small number of users (50 or less) or specific department

Enterprise databases

A multi-user database that supports the overall company and many users across many departments

NoSQL

A new generation of database management systems that is not based on traditional relational database model.

Query language

A nonprocedural language that is used by a DBMS to manipulate its data. An example of a query language is SQL.

Data Management

A process that focuses on data collection, storage, and retrieval. Common data management functions include addition, deletion, modification, and listing.

Query

A question or task asked by an end user of a database in the form of SQL code. A specific request for data manipulation issued by the end user or the application of DBMS.

Business Intelligence

A set of tools and processes used to capture, collect, integrate, store, and analyze data to support business decision making.

Online analytical processing (OLAP

A set of tools that provide advanced data analysis for retrieving, processing, and modeling data from the data warehouse.

Database

A shared integrated structure that contains end user data and metadata (data about data).

Data warehouse

A specialized database that stores historical and aggregated data in a format optimized for decision support.

Structural Dependence

Access to a file is dependent on its own structure. All file system programs are modified to conform to a new file structure.

Manual File Systems

Accomplished through a system of file folders and file cabinets

Database System

An organization of components that defines and regulates the collection, storage, management, and use of data in a database environment.

General-purpose database

Contains a wide variety of data used in multiple disciplines

Discipline-specific database

Contains data focuses on specific subject areas

Data Processing (DP) specialist

Created a computer-based system that would track data and produce required reports

Data processing (DP) specialist

Created a computer-based system that would track data and produce required reports

Cloud database

Created and maintained using cloud data services that provide defined performance measures for the database. (Microsoft Azure or Amazon AWS)

Data Dependence

Data access changes when data storage characteristics change

Structured data

Data has been formatted to facilitate storage, use, and information generation.

Distributed database

Data is distributed across two or more sites

Centralized database

Data is located at a single site

Data Independence

Data storage characteristics is changed without affecting the program's ability to access data

Unstructured data

Data that exists in its original, raw state; that is, in the format in which it was collected.

Operational database/transactional database/online transaction processing database (OLTP)/production database

Designed to support a company's day-to-day operations

Data inconsistency

Different versions of the same data appear in different places.

Structured Query Language (SQL)

Do facto query language and data access standard supported by the majority of DBMS vendors. A powerful and flexible relational database language composed of commands that enable users to create database and table structures, perform various types of data manipulation and data administration, and query the database to extract useful information.

Backup and recovery management

Enables recovery of the database after a failure

Security Management

Enforces user security and data privacy

Performance Tuning

Ensures efficient performance of the database in terms of storage and access speed

Structural Independence

File structure is changed without affecting the application's ability to access data.

Data integrity

In a relational database a condition in which the data in the database complies with all entity and referential integrity constraints.

File System Redux: Modern End-User Productivity Tools

Includes spreadsheet programs such as Excel

Data integrity management

Minimizes redundancy and maximizes consistency

Semi-structured data

Processed to some extent

Data quality

Promoting accuracy, validity, and timeless of data.

Data

Raw facts, such as a telephone number, a birth date, a customer name, and a year-to-date (YTD) sales value. Data have little meaning unless they have been organized in some logical manner.

Islands of information

Scattered data locations. Increases the probability of having different versions of the same data

Multiuser access control

Sophisticated algorithms ensuring that multiple users can access the database concurrently without compromising integrity

Analytical database

Stores historical data and business metrics used exclusively for tactical or strategic decision making

Multi-user database

Supports multiple users at the same time

Single-user database

Supports one user at a time

Knowledge

The body of information and facts about a specific subject. Knowledge implies familiarity, awareness, and understanding of information as it applies to an environment. A key characteristic is that new knowledge can be derived from old knowledge.

Query result set

The collection of data rows returned by query.

Data Design

The process that yields the description of the database structure and determines the database components. The second phase of the Database Life Cycle.

Information

The result of processing raw data to reveal its meaning. Information consists of transformed data and facilitates decision making.

Physical data format

The way a computer "sees" (stores) data.

Logical data format

The way a person views data within the context of a problem domain

Data transformation and presentation

Transforms entered data to conform to required data structures

Data redundancy

Unnecessarily storing same data at different places

Social media

Web and mobile technologies that enable "anywhere, anytime, always on" human interactions.

Practical Significance

of data dependence is the difference between logical and physical format

Advantages of DBMS

• Better data integration and less data inconsistency • Increased end-user productivity • Improved data sharing, security, access, decision making, quality

Disadvantages of DBMS

• Increased costs • Management complexity • Maintaining currency • Vendor dependency • Frequent upgrade/replacement cycles

Roles of DBMS

• Intermediary between the user and the database • Enables data to be shared • Presents the end user with an integrated view of the data • Receives and translates application requests into operations required to fulfill the request • Hides database's internal complexity from the application program