Introduction to Database Systems Flashcards
Data
- raw facts
- building blocks of info
- must be formatted for storage and retrieval of data
Information
- raw data processed to provide meaning
- enables knowledge creation
- supports good decision making when accurate, relevant, and timely
Database
- shared, integrated computer structure storing a collection of logically related data
- contains data dictionary of description of data characteristics and relationships
Metadata
- data about data
Database Management System
- a software system enabling users to define, create, and maintain data
DBMS - Advantages
improves data sharing, security, and access
DBMS - Disadvantages
increased cost w/ requirement for up-to-date hardware, software, and highly skilled personnel
single-user
supports one user at a time
multiuser
supports multiple users at the same time
centralized
data located at a single site
distributed
data distributed across several different sites
cloud
created and maintained using cloud data services providing defined performance measures for the database
operational
supports day-to-day operations of the company
analytical
stores historical and business metrics used exclusively for tactical or strategic decision making
unstructured data
exists in original state
structured data
results from formatting
semi structured data
processed to some extent
extensible markup language (XML)
represents data elements in textual format
database design
focuses on design of the database structure used to store and manage end-user data
file systems
- organized by expected use
- data processing specialist converted computer file structure from manual system to track data and produce required reports
fields
character or group of characters with a specific meaning
records
one or more fields that describes a person, place, or thing
files
collection of related records
data redundancy
same data stored unnecessarily in different places
data anomalies
data abnormalities when all changes in redundant data are not made correctly
structural dependence
access to file dependent on its own structure
- all file system programs must be modified to conform to a new file structure
structural independence
change file structure without affecting data access
data dependence
data access changes when data storage characteristics change
data independence
data storage characteristics changes do not affect data access
system admin
person responsible for overseeing the general operations of the database system
database admin
person responsible for managing the DBMS and ensuring the database is functioning properly
database designer
person responsible for designing and maintaining the databases
database developers
persons responsible for designing, implementing, and maintaining the database-based apps
end-users
persons using the app programs to run the daily operations of the organization
data dictionary management
stores def. of data elements and their relationships (metadata) in a data dictionary
data storage management
performance tuning ensures efficient performance of the database in terms of storage and access speed
security management
creates security system that enforces user security and data privacy
