CIS 310 Ch. 1

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

Cloud database

Created and maintained using cloud data services that provide defined performance measures for the database

Online analytical processing (OLAP)

Tools for retrieving, processing, and modeling data from the data warehouse

Business intelligence

Captures and processes business data to generate information that support decision making

DBMS Functions

-Data dictionary management >data dictionary -Data storage management >performance tuning -Data transformation and presentation >transforms entered data to conform to required data structures -Security management >enforces user security and data privacy -Multiuser access control >sophisticated algorithms ensure that multiple users can access the database concurrently without compromising its integrity -Backup and recovery management >enables recovery of the database after a failure -Data integrity management >minimizes redundancy and maximized consistency -Database access languages and application programming interfaces >query language >SQL -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

Metadata

Data about data, which the end-user data are integrated and managed

Data dependence

Data access changes when data storage characteristics change -Practical significance of it is the difference between logical and physical format

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 -Types: >update >insertion >deletion

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 the data

Database design

Focuses on the design of the database structure that will be used to store and manage end-user data -Well-designed database >Facilitates data management >Generates accurate and valuable information -Poorly designed database causes difficult-to-trace errors

Unstructured data

It exists in their original state

Structured data

It results from formatting -Structure is applied based on type of processing to be performed

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 -Eliminates most of file system's problems -Current generation software: >Stores data structures, relationships between structures, and access paths >Defines, stores, and manages all access paths and components

Semistructured data

Processed to some extent

Extensible Markup Language (XML)

Represents data elements in textual format

DBMS

Role of the _____(acronym): -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 requests -Hides database's internal complexity from the application programs and users

Islands of information

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

Database

Shared, integrated computer structure that stores a collection of: -End-user data - Raw facts of interest to end user -Metadata: Data about data, which the end-user data are integrated and managed >Describe data characteristics and relationships

Data warehouse

Stores data in a format optimized for decision support

Analytical database

Stores historical data and business metrics used exclusively for tactical or strategic decision making -Data warehouse -Online analytical processing (OLAP)

Workgroup databases

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 -Workgroup databases -Enterprise database

Single-user database

Supports one user at a time -Desktop database: Runs on PC

Evolution

_________ of file system data processing: -Manual File Systems (accomplished through a system of file folders and filing cabinets)--> -Computerized File Systems (data processing (DP) specialist: created a computer-based system that would track data and produce required reports)--> -File System Redux: Modern End-User Productivity Tools (includes spreadsheet programs such as Microsoft Excel)

Disadvantages

__________ of database systems: -increased costs -management complexity -maintaining currency -vendor dependence -frequent upgrade/replacement cycles

Advantages

__________ of the DBMS: -Better data integration and less data inconsistency -Increased end-user productivity -Improved: >Data sharing >Data security >Data access >Decision making -Data quality: Accuracy, validity, and timeliness of data

Problems

__________ with file system data processing: -lengthy development times -difficulty of getting quick answers -complex system administration -lack of security and limited data sharing -extensive programming