Chapter 11 Flashcards
database
collection of data organized in a manner that allows access, retrieval, and use of that data
data
collection of unprocessed items (text, numbers, images, audio, video)
information
processed data
Database Management System (DBMS)
allows users to create a computerized database, add/modify/delete data, sort and retrieve data, and create forms/reports from the data
Data is organized in levels
hierarchy- each higher level of data consists of one or more items from the lower level (characters, field records, and files)
character
one byte
field
a combo of one or more related characters (given field size and data type)
data type
specifies the kind of data a field can contain and how the field is used
record
a group of related fields
data file
a collection of related records that’s stored on a storage medium
primary key
a field that uniquely identifies each record
composite key
when the primary key is made up of multiple fields
file maintenance
the procedures that keep data current- adding, modifying, and deleting records
validation
compares data with a set of rules or values to find out if the data meets certain criteria
file processing system
each department has its own set of files, redundant data, and isolated data.
database approach
programs and users share data reduced data redundancy improved data integrity shared data easier access reduced development time
back end
the DBMS
front end
a program that generally has a more user-friendly interface than the DBMS (webpage)
collaborative databases
where users store and share photos, videos, recordings, and other personal media
database server
stores and provides access to a database
data model
defines how users view the organization of thedata
3 types of data models are:
relational, object-oriented, and multidimensional
relational database
stores data in tables that consist of rows and columns
object-oriented database
stores data in objects
multidimensional database
stores data in dimensions
data dictionary aka repository
contains data about each file in the database and each field in those files
DBMS tools
query language, query by example, form, and report writer
query
a request for specific data from the database
query language
consists of simple, English-like statements that allows users to specify the data to display, print, store, update, or delete
Structured Query Language (SQL)
a popular query language that allows users to manage, update, and retrieve data
form
a window on the screen that provides areas for entering or modifying data in the database
report writer
allows users to design a report on the screen, retrieve data into the report design, and then display or print the report
access privileges
define the actions that a specific user or group of users can perform on the data
principle of least privilege policy
where users’ access privileges are limited to the lowest level necessary to perform required tasks to prevent accidental or intentional misuse of the data
backup
a copy
log
a listing of activities that modify the contents of the database
recovery utility
uses logs and/or backups and either rollforward or rollback techniques to restore a database when it becomes damaged or destroyed
forward recovery (rollforward)
uses log to reenter changes made to the db since the last save or backup
backward recovery (rollback)
uses the log to undo any changes made to the db during a certain period- restores the db to its condition prior to the failure
continuous backup
a backup plan in which changes are backed up as they are made
