Chapter 5 Flashcards
data governance
managing information across an entire organization
master data management
process that spans all of the business processes and applications.
master data
set of core data, such as customer, product, employee, vendor, geographic location. Spans all of the enterprises information system.
databases
provides all users with access to the data.
What does database sytems minimize?
data redundancy, data isolation, data inconsistency.
what do database systems maximize?
data security, data integrity, data interdependence.
bit (binary digit)
smallest unit of data a computer can process. 0’s or 1’s.
data hierarchy
database-file-record-field-byte-bit
byte
represents single characters
data model
diagram respresenting entities in the database and their relations.
instance
specific or unique representation of an entity
attribute
characterstic of quality of an entity.
primary key
unique identifier
secondary keys
other fields not representing the file with complete accuracy.
entity relationship modeling
ER diagram. association between two entitites. Diagrams entities, attributes, and relationships.
cardinalilty
in entity relationship model. refers to maximum number of instances for entity. 1 or many.
modality
in entity relationship mod. refers to minimum number of instances for entity. 0 or 1
identifiers
primary key
relational database model
two dimensional tables- big files=flat files
structured query language
most popular language. used to perform searches with simple statements or keywords. May include key words like SELECT, FROM, WHERE…
query by example
user fills out grid or template to construct a sample. Drag and drop.
data dictionary
defines the appropriate format for entering the data into the database. Provides information on each attribute.
Normalization
reduces relational databases for minimum redundancy, maximum data integrity, and optimal processing performance. Depend only on the primary key.
Data warehouse
repository of historical data organized by subject to support decision makers in the organization. Expensive and usually used by larger companies.