Introduction to Database CIT180

File

A collection of related records

Business Intelligence

(Type of Database) Captures and processes business data to generate information that support decision making

Online Analytical Processing (OLAP)

(Type of Database) Enable retrieving, processing, and modeling data from the data warehouse

Unstructured Data

(Type of Database) It exists in their original state

Structured Data

(Type of Database) It results from formatting Structure is applied based on type of processing to be performed

Semistructured Data

(Type of Database) Processed to some extent

Extensible Markup Language (XML)

(Type of Database) Represents data elements in textual format

Data Warehouse

(Type of Database) Stores data in a format optimized for decision support

Database Management System (DBMS)

Collection of programs Manages the database structure Controls access to data stored in the database

General-purpose Databases

Contains a wide variety of data used in multiple disciplines

Discipline-specific Databases

Contains data focused on specific subject areas

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

Data

Raw Facts Building blocks of info Data Management Tends to have little meaning unless organized in some logical manner

End-user data

Raw facts of interest to end user

Poor-Designed Database

Causes difficult-to-trace errors

Evolution of File System Data Processing

1. Manual File Systems (Accomplished through a system of file folders and filing cabinets) 2. Computerized File Systems (Data processing (DP) Specialist) 3. File System Redux: Modern End-User Productivity Tools (Includes spreadsheet programs such as Microsoft Excel)

Field

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

Record

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

Database Communication Interfaces

Accept end-user requests via multiple, different network environments

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)

Advantages of DBMS

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

Metadata

Data about data, which the end-user data are integrated and managed. (Describes data characteristics and relationships)

Data Dependence

Data access changes when data storage characteristics change

DBMS Functions

Data dictionary management Data storage management Data transformation and presentation Security management Multiuser access control Backup and recovery management Data integrity management Databases access languages/application programming interfaces Database communication interfaces

Distributed Database

Data is distributed across different 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 the data

Structured Query Language (SQL)

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

Operational Database

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

Data Anomaly

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

Practical Significance of Data Dependence

Difference between logical and physical format

Data Inconsistency

Different versions of the same data appear in different places

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

Lack of Design and Data-Modeling Skills

Evident despite availability of multiple personal productivity tools available Data-modeling skills is vital in the data design process Good data modeling facilitates communication between designer, user, and developer

Well-designed Database

Facilitates data management Generates accurate and valuable information

Structural Independence

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

Database Design

Focuses on the structure that will be used to store/manage end-user data

Data Management

Generation, storage, and retrieval of data

Disadvantages of Database Systems

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

Role of DBMS

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

Problems with File System Data Processing

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

Query language

Lets the user specify what must be done without having to specify how

Database Systems

Logically related data stored in a single logical data repository Physically distributed among multiple storage facilities DBMS eliminates most of file system's problems

Data Integrity Management

Minimizes redundancy and maximizes consistency

Raw Data

Not yet been processed to reveal the meaning

Data Redundancy Implications

Poor data security Data inconsistency Increased likelihood of data-entry errors when complex entries are made in different files Data anomaly

Information

Produced by processing data Reveals the meaning of data Enables knowledge creation Should be accurate, relevant, and timely to enable good decision making

Data Quality

Promoting accuracy, validity, and timeliness of data

Desktop Database

Runs on PC

Islands of Information

Scattered data locations (increases probability of having different versions of the same data)

Database

Shared, integrated computer structure that stores a collection of end-user data and metadata.

Multiuser Access Control

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

Current Generation DBMS Software

Stores data structures, relationships between structures, and access paths Defines, stores, and manages all access paths and components

Data Dictionary

Stores definitions of the data elements and their relationships

Analytical Database

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

Workgroup Database

Supports a small number of users or a specific department

Enterprise Database

Supports many users across many departments

Multiuser Database

Supports multiple users at the same time

Single-user Database

Supports one user at a time

Data Transformation and Presentation

Transforms entered data to conform to required data structures

Data Redundancy

Unnecessarily storing same data at different places

Types of Data Anomaly

Update Anomalies Insertion Anomalies Deletion Anomalies