Exam One Flashcards
according to a McKinsey Global Institute Report, in 2010 alone, global enterprises stored more than
7 million exabytes of data
program-data independence, planned data redundancy, improved data consistency, improved data sharing, increased productivity of application development, enforcement of standards, improved data quality, improved data accessibility and responsiveness, reduced program maintenance, improved decision support
advantages of database approach
legacy systems contain what data and are hosted where
poor, mainframes
proof of concept time
1960s
creating, updating, storing, and retrieving data from a database
primary purposes of a database management system
iterative process of system development in which requirements are converted to a working system that is continuously revised between analysts and users
prototyping
individuals and interactions over processes and tools, working software over comprehensive documentation, customer collaboration over contract negotiation, responding to change over following a plan
agile software development
database that supports one user
personal database
database that can include ERP
enterprise applications
database that is multi-tiered client/server
departmental database
failure to implement a strong database administrative function
most common source of database failures in organizations
new specialized personnel, installation and management cost and complexity, conversion costs, need for explicit backup and recovery, organizational conflict
costs and risks of database approach
software system that enables the use of a database approach
database management system
organized collection of logically related data
database
stored representation of objects and events that have meaning and importance in the user’s environment
data
data that has been processed in such a way that the knowledge of the person who uses the data is increased
information
data that describes properties or characteristics of data
metadata
application program that is used to perform a series of database activities on behalf of database users
database applications
program-data dependence, duplication of data, limited data sharing, lengthy development times, excessive program maintenance
disadvantages of file processing systems
graphical systems used to capture the nature and relationships among data
data models
a person, place, object, event, or concept in the business environment
entity
establish the relationships between entities by means of common fields included in a logical structure called a relation
relational database
detailed, well-planned development process, long, time-consuming but comprehensive, process measured by milestones
system development life cycle
faster and more adaptive, especially when DB is in place already, embeds customer within the development process/collaboration
rapid application development
user views, can be determined from business
external schema
schema of developing entities
conceptual schema
logical and physical schemas, inside of DB
internal schema
detailed, logical representation of the data for a business
entity-relationship model
statement that defines or constrains some aspect of the business
business rule
declarative, precise, atomic, consistent, expressible, distinct, business-oriented
what business rules are
collection of entities that share common properties or characteristics
entity type
single occurrence of an entity type
entity instance
attribute or combination of attributes that uniquely distinguishes each occurrence
identifier
property or characteristics of an entity type that is of interest to the business
attribute
meaningful association between or among entity type
relationship type
association between or among entity instances, each relationship instance associates exactly one entity instances from each participating entity type
relationship instance
entity type that associates the instances of one or more entity types
associative entity
number of instances of an entity that can or must be associated with each instance of another entity
cardinality constraint
number of entity types that participate in a relationship
degree
creating, updating, removing data
what business policies and rules govern
business characteristics, meaningful, unique, readable, composed of words taken from an approved list, repeatable, standard syntax
what data names should be
subgrouping of the entities in an entity type that is meaningful to a business
subtype
generic entity type that has a relationship with one or more subtypes
supertype
property by which subtype entities inherit values of all attributes and instance of all relationships of the supertype
attribute inheritance
process of defining a more general entity type from a set of more specialized entity types, bottom-up
generalization
process of defining one or more subtypes of the supertype and forming supertype/subtype relationships, top-down
specialization
addresses supertype/subtype relationship
completeness constraint
each entity instances of the supertype must be a member of some subtype in the relationship
total specialization
an entity instances of the supertype is allowed to not belong to any subtype
partial specialization
addresses whether an instance of a supertype may simultaneously be a member of two or more subtypes
disjointedness constraint
if an entity instances (supertype) is a member of one subtype, it cannot simultaneously be a member of any other subtype
disjoint rule
attribute of a supertype whose values determine target subtype
subtype discriminator
an entity instance can simultaneously be a member of two or more subtypes
overlap rule
data descriptions being written into programming code
what program-data dependence is caused by
a good data definition will describe all of the characteristics of a data object EXCEPT
who can delete data
hierarchical arrangement of supertype and subtypes, where each subtype has only one supertype
supertype/subtype hierarchy
