chapter 2 review Flashcards
what provides for data collection, storage, and retrieval?
the information system
the information system is composed of six components which are?
people
hardware
software
programs
procedures
databases
the process that establishes the need for and extent of an information system?
system analysis
process of creating an information system?
system development
transforms data into information that forms the basis for decision-making?
applications
usually, applications produce the following three components?
formal reports
tabulations
graphic displays
applications are composed of the following two parts
data
code
program instructions?
code
performance depends on three factor?
d
a
a
database design and implementation
application design and implementation
administrative procedures
process of database design and implementation
db development
implementation phase include?
c
L
p
creating database storage and structure
loading data into database storage structure
providing for data management
DB design and application development mapped out and evaluated. is the def of?
SDLC
system development life cycle
SDLC is divided into the following five phases:
planning
analysis
detailed system design
implementation
and maintenance
general overview of company objectives?
planning
assessments of flow and extent requirements?
C
M
R
should the existing system be continued
should the existing system be modified
should the existing system be replaced
study and evaluate alternate solutions by?
T
S
O
technical aspects of hardware and software requirements
system costs
operational cost
problems defined during the planning phase are examined in greater detail in which stage?
analysis
t or f : thorough audit of user requirements in the analysis phase
true
t or f: only hardware systems are being studied
false
goals of the analysis phase are the understanding of?
S
A
O
system function area
actual and potential problems
oppertunities
the designer completes the design of the system process in which stage?
detailed system design
t or f: the designing phase include all necessary technical specification?
true
hardware, software, DBMS software, and application programs are being installed at which stage?
implementation
t or f: the cycle of coding, testing, and debugging continues until DB is ready for delivery in the planning phase?
false
DB is created and the system is customized by?
C
U
creating of tables and views
user authorization
three types of maintenance activity?
C
A
P
corrective maintenance
adaptive maintenance
perfective maintenance
produce better systems within a reasonable amount of time and cost?
CASE
computer aided systems engineering
t or f: CASE produced applications that are unstructured,undocumented, and not standarized?
false
what are the six phases in the DBLC?
I
D
i L
t e
o
m
initial study
design
implementation and loading
testing and evaluation
operation
maintenance and evolution
DB initial study overall purpose:
A
D
D
D
analyze company situation
define problems and constraints
define objectives
define scope and boundaries
t or f: interactive and iterative processes required to complete the first phase of DBLC?
True
general conditions in which the company operates, its organizational structure, and its mission. is in which stage?
initial study
t or f: in the initial study, discover what the company’s components are, and how they function, and how they interact.
true
in the initial study. defining problems and constraints by?
F
F
A
formal and informal information sources,
finding precise answers is important ,
accurate problem definition does not always yield a solution.
t or f: DB system objectives must correspond to those envisioned by end users?
true
extent of design according to operational requirements?
scope
limits external to the system
boundaries
necessary to concentrate on data characteristics required to build a database model. this is which phase?
DB design
two views of data within the system:
business view
designer view
this view described data as an information source.
business view
this view describes data structure, access, and activities required to transform data into information.
designer view
actually, implement all design specifications from the previous phase. this phase is?
implementation and loading
the implementation phase consists of:
i
c
L
install DBMS
create the DB
load and converts data
creates logical representations of computing resources independent of physical resources?
virtualization
occurs in parallel with applications programming?
testing and evaluation
if implementation fails to meet some of the system’s evaluation criteria:
F
m
u
fine-tune specific system and DBMS configuration parameters
modify physical or logical design
upgrade hardware or software platforms
enforced via proper use of primary, and foreign key rules
integrity
types of backup recovery:
f
d
t
full
differential
transactional
once DB passed the evaluation stage, it is considered….
operational
problems not foreseen during testing surface, the solutions may include:
L
i
load-balancing software to distribute transactions among multiple computers
increasing available cache
required periodic maintenance include:
P
C
A
G
P
P
preventing maintenance (backup)
corrective maintenance(recovery)
adaptive maintenance
assignment of access permissions and their maintenance for new and old users
generation of DB access statistics
periodic security audits
periodic system usage summaries
data modeling creates an abstract DB structure, this is the def of?
conceptual design
t or f: conceptual design embodies a clear understanding of business and its functional area?
true
how many steps are required in the conceptual design?
4
discovers data element characteristics and obtains characteristics from different sources?
data analysis and requirements
t or f: data analysis requires a thorough understanding of the company’s data types and their extent and uses.
true
designer enforces standards in design documentation in the?
entity relationship modeling and normalization
t or f: designers use diagrams and symbols, documentation writing style, layout, and other conventions?
true
is a communication tool as well as design blueprint?
ER model
verified against proposed system processes?
data modeling verification
revision of original design consists of:
C
D
careful reevaluation of entities
detailed examination of attributes describing entities
information system components that handle specific function
module
subset of a DB stored at a given location
DB fragment
t or f: portions of DB reside in the same physical location?
false
t or f: processes accessing the database are the same from one location to another?
false
common factors affecting purchasing decisions:
C
D
U
P
D
cost
DBMS features and tools
underlying model
portability
DBMS hardware requirements
translates software independent conceptual model into software dependant model?
logical design
mapping steps involve:
s
s
w
b
h
strong entity
supertype relationship
weak entity
binary relationships
higher degree relationships
t or f: all defined constraints must be supported by the logical data model?
true
special attention should be placed at this stage to ensure security…..
is enforced
validate logical model integrity constraints ensures that:
A
s
all views can be resolved
security is enforced to ensure the privacy of the data
validate all logical model definitions against all end-user data, transaction, and security requirements is the….
final step in the logical design process
process of selecting data storage and data access charactereistics of DB?
physical design
storage characteristics are a function of:
D
T
D
device types supported by hardware
types of data access method supported by system
DBMS
t or f: physical design is more complex when data are distributed?
true
the designer must determine several attributes:
V
U
data volume
data usage patterns
data storage influence:
L
W
W
locations and physical storage organizations for each table
what indexes and the type of indexes to be used for each table
what views and the type of views to be used on each table
set of database privileges that could be assigned as a unit to a user or group
database role
assign security controls by:
S
c
specific access rights on DB objects to a user or group of users
can also revoke during operation to assist with backups or maintenance events
performance can be affected by characteristics:
s
s
s
a
storage media
seek time
sector and block size
and more
t or f: fine tuning the DBMS and queries to ensure that they will meet end-user performance requirements
true
