C175 Chapter 1

Common problems do a collection of spreadsheets created by end users share with the typical file system?

1. End users create their own, private, copies of the data, which creates issues of data ownership 2. Creates islands of information where changes to one set of data are not reflected in all of the copes of the data 3. Lack of data consistency. Since the data in various spreadsheets may be intended to represent a view of the business environment, a lack of consistency in the data may lead to faulty decision making

Physical data format

The way a computer "sees" (stores) data

Data anomaly

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

DBMS make data management more efficient and effective by:

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 end-user productivity

Cost of implementing a database system

1. Increased acquisition and operating costs 2. Management complexity 3. Maintaining currency 4. Vendor dependence

Summary of information

1. Information is produced by processing data 2. Information is used to reveal the meaning of data 3. Good, relevant, and timely information is the key to good decision making 4. Good decision making is the key to organizational survival in a global environment

Uncontrolled data redundancy causes:

1. Poor data security 2. Data inconsistency 3. Data-entry errors 4. Data integrity problems

Functions of a DBMS

1. The DBMS stores the definitions of data and their relationships (metadata) in a data dictionary; any changes made are automatically recorded in the data dictionary. 2. The DBMS creates the complex structures required for data storage. 3. The DBMS transforms entered data to conform to the data structures in item 2. 4. The DBMS creates a security system and enforces security within that system. 5. The DBMS creates complex structures that allow multiple user access to the data. 6. The DBMS performs backup and data recovery procedures to ensure data safety. 7. The DBMS promotes and enforces integrity rules to eliminate data integrity problems. 8. The DBMS provides access to the data via utility programs and from programming languages interfaces. 9. The DBMS provides end-user access to data within a computer network environment.

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

Field

A character or a group of characters (numeric or alphanumeric) that describes a specific characteristic. A field may define a telephone number, a date, or other specific characteristics that the end user wants to keep track of

Data dependence

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

Record

A logically connected set of one or more fields that describes a person, place, event, or thing

Why the cost of ownership may be lower with a cloud database versus a company database?

Cloud databases reside on the Internet instead of within the organization's own network infrastructure. This can reduce costs because the organization is not required to purchase and maintain the hardware and software necessary to house the database and support the necessary levels of system performance

Summary of data

Data constitute the building blocks of information

Data transformation and presentation

Exists to transform any data entered into required data structures. By using this function, the DBMS can determine the difference between logical and physical data formats

Hashed files

Files are encrypted using hash functions that convert data consisting of various formats into numeric values

Heap files

Files containing an unsorted set of records that are uniquely identified by a record id which allows them to be inserted or deleted using that id

Flat files

Files having no internal hierarchy

Index files

Files that store a list of lookup field values from a data file

File

Historically, a collection of file folders, properly tagged and kept in a filing cabinet. Although such manual files still exist, we more commonly think of a (computer) file as a collection of related records that contain information of interest to the end user

Islands of information

In the old file system environment, pools of independent, often duplicated, and inconsistent data created and managed by different departments

Data

Raw facts from which the required information is derived. Data have little meaning unless they are grouped in a logical manner

Data dictionary management

Removes structural and data dependency and provides the user with data abstraction. The DBMS uses this function to look up the required data component structures and relationships

Security management

Sets rules that determine specific users that are allowed to access the database. This function also sets restraints on what specific data any user can see or manage

Basic database functions that a spreadsheet cannot perform

Spreadsheets do not support self-documentation through metadata, enforcement of data types or domains to ensure consistency of data within a column, defined relationships among tables, or constraints to ensure consistency of data across related tables

Logical data format

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

Business intelligence

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

Structural dependence

a file is dependent on its structure

Desktop database

a single-user database that runs on a personal computer

Data warehouse

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

Data integrity

as the condition in which all of the data in the database is consistent with the real-world events and conditions

Knowledge

body of information and facts about a specific subject

Data independence

can change the data storage characteristics without affecting the program's ability to access the data

Structural independence

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

General-purpose database

contain a wide variety of data used in multiple disciplines

Discipline-specific databases

contain data focused on specific subject areas

Cloud database

created and maintained using cloud data services, such as Microsoft Azure of Amazon AWS

Metadata

data about data, through which the end-user data is integrated and managed

Operational database, also known as an online transaction processing (OLTP) database, transactional database, or production database

designed primarily to support a company's day-to-day operations

Data inconsistency

exists when different versions of the same data appears in different places

Analytical database

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

NoSQL (Not only SQL)

generally used to describe a new generation of database management systems that is not based on the traditional relational database model

Semistructured data

has already been processed to some extent

Database management system (DBMS)

is a collection of programs that manages the database structure and controls access to the data stored in the database

Data quality

is a comprehensive approach to promoting the accuracy, validity, and timeliness of the data

Summary of a database

is a computer structure for storing data in a shared, integrated fashion so that the data can be transformed into information as needed

Data management

is a discipline that focuses on the proper generation, storage, and retrieval of data

query language

is a nonprocedural language—one that lets the user specify what must be done without having to specify how

Online analytical processing (OLAP)

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

Database

is a shared, integrated computer structure

Extensible Markup Language (XML)

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

Query

is a specific request issued to the DBMS for data manipulation

Ad hoc query

is a spur-of-the-moment question

Unstructured data

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

Structured Query Language (SQL)

is the de facto query language and data access standard supported by the majority of DBMS vendors

Structured data

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

Information

is the result of processing raw data to reveal its meaning (produced by processing data)

Structural independence is important because

it substantially decreases programming effort and program maintenance costs

Data processing (DP) specialist

person responsible for developing and managing a computerized file processing system

Database system

refers to an organization of components that define and regulate the collection, storage, management, and use of data within a database environment

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

Data redundancy

same data is stored unnecessarily at different places

Workgroup database

supports a relatively small number of users (usually fewer than 50) or a specific department within an organization

Distributed database

supports data distributed across several different sites

Centralized database

supports data located at a single site

Multiuser 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

Performance tuning

the activities that make the database perform more efficiently in terms of storage and access speed

Query result set

the answer the DBMS sends back to the application

Enterprise database

used by the entire organization and supports many users (more than 50, usually hundreds) across many departments