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