Data
raw facts, building blocks of information
Information
data in context which is processed to reveal meaning. THE BEDROCK OF KNOWLEDGE
Database
shared, integrated computer structure that stores a collection of end-user data and metadata.
DBMS
the intermediary between the user and the database
Ways Databases are Classified
number of usersdatabase locationsexpected type and extent of use
Single-user database (desktop database)
supports only one user at a time (desktop)
Multi-user database (workgroup database)
supports multiple users at the same time (workgroup and enterprise)
Centralized database
data located at a single site
Distributed database
data distributed across several sites
Operational database
supports a company's day-to-day operations also known as an online transaction processing (OLTP), transactional, or production database
Data warehouse
stores data used for tactical or strategic decisions
Extensible Markup Language (XML)
represents data elements in textual format
Manual file systems
served as a data repository for small data collections. Cumbersome for large collections
Computerized file systems
Data processing specialist converted computer file structure from manual system
File system
extensive programmingcannot perform ad hoc queriessystem administration is complex and difficultdifficult to make changes to existing structuressecurity features are likely to be inadequate
Structural independence
change file structure without affecting data access
Data independence
data storage characteristics do not affect data access
Data redundancy
same data stored unnecessarily in different places
Hardware
all the system's physical devices
Software
operating system, DBMS, and application programs and utility
Data management
a discipline that focuses on the proper generation, storage, and retrieval of data. Given the crucial role that data play.
Metadata
data about data, through which the end-user data are integrated and managed.
Data inconsistency
when different versions of the same data appear in different places.
query
a specific request issued to the DBMS for data manipulation, predefined and routinely processed.
ad hoc query
is created to obtain information as the need arises
query result set
results of the query
Data quality
a comprehensive approach to promoting the accuracy, validity, and timeliness of the data.
enterprise database
When the database is used by the entire organization and supports many users (more than 50, usually hun- dreds) across many departments
General-purpose databases
contain a wide variety of data used in multiple disciplines—for example, a census database that contains general demographic data
Discipline-specific databases
contain data focused on specific subject areas
analytical databases
focus primarily on storing historical data and business metrics used exclusively for tactical or strategic decision making
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
business intelligence
describes a comprehensive approach to capture and process business data with the purpose of generating information to support business decision making.
Unstructured data
data that exist in their original (raw) state—that is, in the format in which they were collected
Structured data
the result of formatting unstructured data to facilitate storage, use, and the generation of information
Semistructured data
Data thats already been processed to some extent
NoSQL
(Not only SQL) is generally used to describe a new generation of database management systems that is not based on the traditional relational database model
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.
logical data format
how the human being views the data
physical data format
how the computer must work with the data
data anomaly
when not all of the required changes in the redundant data are made successfully (update anomaly, insertion anomaly, deletion anomaly)
database system
refers to an organization of components that define and regulate the collection, storage, management, and use of data within a database environment
five components of a database system environment
1. Hardware2. Software3. People4. Procedures5. Data
Performance tuning
relates to the activities that make the database perform more efficiently in terms of storage and access speed
query language
a nonprocedural language—one that lets the user specify what must be done without having to specify how
Structured Query Language (SQL)
The de facto query language and data access standard supported by the majority of DBMS vendors
Negatives of Databases
1. Increased Costs2. Management Complexity3. Maintaining Currency4. Vendor Dependence5. Frequent upgrading/replacement
4 complex database technologies
1. Very Large Databases2. Big Databases3. In memory Databases4. Cloud Databases