CIS 3365 - CH 1 - Database Systems

Field

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

Data management

A discipline that focuses on the proper generation, storage and retrieval of information

Database Management System (DBMS)

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

Databases can also be classified to reflect the degree to which the data is structured:

Unstructured data and structured data semi-structured

types of data anomalies

Update Anomalies, Insertion Anomalies, Deletion Anomalies

A DBMS provides several advantages

1. Improved data sharing 2. Improved data security 3. Better data integration 4. Minimized data inconsistency 5. Improved data access 6. Improved decision making 7. Increased user productivity

ad hoc query

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

File

A collection of related records

Data Quality

A comprehensive approach to ensuring the accuracy, validity, and timeliness of data.

data independence

A condition in which data access is unaffected by changes in the physical data storage characteristics.

data dependence

A data condition in which data representation and manipulation are dependent on the physical data storage characteristics.

cloud database

A database that is created and maintained using cloud services, such as Microsoft Azure or Amazon AWS.

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.

query language

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

Database

A shared, integrated computer structure that stores a collection of the following...

desktop database

A single-user database that runs on a personal computer.

performance tuning

Activities that make a database perform more efficiently in terms of storage and access speed.

database system

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

Data storage management

DBMS creates and manages complex structures required for data storage

operational database

Designed to support a company's day-to-day operations (online transaction processing (OLTP) database, transactional database, or production database.)

Data

Raw facts that have not been processed to reveal meaning to the end user

data processing (DP) specialist

The person responsible for developing and managing a computerized file processing system.

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.

Typically, analytical databases comprise two main components

a data warehouse and an online analytical processing front end

Online analytical processing (OLAP)

a set of tools that work together to provide an advanced data analysis environment for retrieving, processing, and modeling data from the data warehouse

Extensible Markup Language (XML)

a special language used to represent and manipulate data elements in a textual format

data warehouse

a specialized database that stores data in a format optimized for decision support

Query

a specific request issued to the DBMS for data manipulation

structural dependence

access to a file is dependent on its structure, a change in the database schema affects data access, thus requiring changes in all access programs

Knowledge

body of information and facts about a specific subject. New knowledge can be derived from old knowledge.

general-purpose database

contain a wide variety of data used in multiple disciplines

discipline specific databases

contain data focused on a specific subject

Metadata

data about data, through which the end users data is organized. Metadata provides a more complete picture of the data in the database

unstructured data

data that exists in its original (raw) state that is, in the format in which it was collected

Semi-structured

data that has already been processed to some extent

NoSQL

database management systems that are not based on the traditional relational database model. NoSQL databases are designed to handle the unprecedented volume of data, variety of data types and structures, and velocity of data operations that are characteristic of these new business requirements

distributed database

database supports data distributed across several sites

centralized database

database supports data located at a specific site

Data dictionary management

defines data elements and their relationships

business intelligence

describes a comprehensive approach to capture and process business data with the purpose of generating information to support business decision making

Data anomoly

develops when NOT all of the required changes in the redundant data are made successfully

Data redundancy

exists when the same data is stored unnecessarily at different places

structural independence

exists when you can change the file structure without affecting the application's ability to access the data

Analytical database

focuses primarily on storing historical data and business metrics used exclusively for tactical or strategic decision making

In some contexts, such as research environments, a popular way of classifying data- bases is according to the type of data stored in them. Using this criterion, databases are grouped into two categories:

general-purpose and discipline-specific databases

a database system is composed of the five major parts

hardware, software, people, procedures, and data

Database design

refers to the activities that focus on the design of the database structure that will be used to store and manage end-user data

Social media

refers to web and mobile technologies that enable "anywhere, anytime, always on" human interactions

islands of information

storage of the same basic information in different locations

Work group database

supports a small number of users, usually less than 50 in a workplace setting

enterprise database

supports many users across many departments (more than 50 usually hundreds)

multi-user database

supports multiple users at the same time

single-user database

supports only one user at a time

XML database

supports the storage and management of semistructured XML data

A DBMS performs several important functions that guarantees

the integrity and consistency of the data in the database

The key to good decision making is

the productions of accurate, timely and relevant information

End user data

the raw facts of interest to the end user

Structured data

the result of formatting unstructured data to facilitate storage, use, and the generation of information

Problems associated with file systems,

• Lengthy development times • Difficulty of getting quick answers • Complex system administration • Lack of security and limited data sharing • Extensive programming

Uncontrolled Data Redundancy sets the stage for the following:

• Poor data security • Data inconsistency • Data-entry errors • Data integrity problems