Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
50 Cards in this Set
- Front
- Back
transaction processing
|
early business IS designed to collect and store data related to accting & financial transactions only. triggered by economic events
|
|
problems associated with transaction based approach
|
-limited data are collected
- important data ay have no direct financial impact -modern data needs are extensive and complex. -financial transaction processing doesn't meet these needs. |
|
Event processing
|
business events are not necessarily associated with economic impacts
-collect when when business even occurs -organization defines "business event" -could use dfd to determind inputs |
|
transaction processing
|
financial transactions
-direct, measurable economic impacts -data needs are driven by specific sysems, function areas and processes |
|
event processing
|
collect more complex data
-organization wide data needs |
|
file mgmt
|
collecting, organizing, storing, retrieving and manipulating data maintained in a file oriented data processing environment. not the same thing as a database.
|
|
flat file
|
each different typle of transaction has a separate fild associated with it.
|
|
problems with flat file systesm
|
1)data redundancy. ok if back up.
2)data integrity - data have not been altered 3)data independence - separating data from programs that use it 4) poor data control/ difficult maintenance 5)privacy |
|
schema
|
complete description of the configuration of record tpes and data items. defines the logical structure and organizational view of the data
|
|
subschema
|
- a description of a portion of a chema DMBS map each user's view of the data from subschemas to schemas
|
|
DBMS
|
set of computer programs that controls the creation, maintenance and the use of the database in a computer platform or of an org and its end users
|
|
query language
|
used to access DB and produce inquiry reports
|
|
logical view
|
how data appear to end user (table)
|
|
physical
|
physical storage of data
|
|
lost update problem
|
multiple simultaneous users
|
|
enterprise
|
large organizational db with many users
|
|
personal
|
smaller simplistic db that could be run on a pc
|
|
character
|
a letter or number
|
|
field
|
a collection of related chars such as customer number (column)
|
|
record
|
colelction of related data fields associated with a perticular person (row)
|
|
file
|
a collection of related records
|
|
record layout
|
describes the fields making the record
|
|
metadata
|
data that describe data
|
|
relationship
|
a connection between individual records in a table and between records in other tables
|
|
attribute
|
a property or character whose value describes each entity in an entity set
|
|
simple attribute
|
cant be broken down
|
|
composite attribute
|
can break down further
|
|
identifier attribute
|
something that has to be unique to everyone
|
|
single valued attribute
|
student dob
|
|
multivalued attribute
|
studnet phone
|
|
model
|
a copy or representation of something
|
|
dfd
|
business processes and data flows
|
|
erd
|
"data base" blueprint for relational db structure. how data are represented and stored
|
|
3 reasons to model a system
|
focus, communicate, verify
|
|
data model
|
a graphical textual representation of data we want to store, retrieve and manipulate.
|
|
entity
|
a single object, a row in a db, a single instance of an entity set
|
|
entity set
|
a colelction of related objects, a table
|
|
key
|
a single attribute or set of attributes that uniquely id each ientity in a table
|
|
domain
|
acollection of all possible legal values an attribue may take
|
|
degree
|
number of entity sets in a relationships. unary/binary/ternary
|
|
dfd
|
process modelign
|
|
erd
|
data modeling
|
|
entity integrity
|
guarantees each entity in a table has a unique value
|
|
regerential integrity
|
the attribue value on the amny side of the relationship
|
|
normalization
|
process of minimizing the duplication of information. corrects logical and structural problems
|
|
higher levels of normalization
|
> slower processing.
-more tables and more relationships between tables. more time required to find a piece together data from queries |
|
normalization
|
there is generally a tradeoff between higher levels of normalization and speed. as redundancy is reduced, the time it takes a the db to process a query typically increases
|
|
foreign key
|
many side
|
|
primary key
|
needed in both tables
|
|
multi-valued attribute
|
a field/colum that can have multiple values in a single space or cell
|