• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/29

Click to flip

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;

29 Cards in this Set

  • Front
  • Back
A specific data file was created for each application?
File Oriented Processing
Create a single data repository to support numerous applications?
Data Oriented Processing
Flat file problems with data redundancy? (4)
1. data storage-lots of it
2. data updating-any changes have to be done multiple times
3. currency of info- may not update all relevant files ea. time
4. Task-Data dependency- user's inability to obtain additional information on his or her needs
Advantages of centralized Database?
1. No data redundancy
2. Single update
3. current values
4. Task-data independence
Disadvantages of Centralized Database?
-can be costly to implement
-can only run in certain operating environments
-have to train users
Tables in a Relational Database:
Rows are called____?
Instances or Records
Tables in a Relational Database:
Columns are called____?
Fileds
Columns in a tables represent ___ of an entity? Example
Attributes- "date"
TRUE/FALSE
Can a primary key have more than on attribute?
True- its called a COMPOSITE KEY
Tables in an actual relational database are linked together via the use of ___&____?
Primary and Foreign keys
A primary uniquely identifies an ____?
Instance
-ex. sales invoice# uniquely identifies a sales transaction
Change of the customers address has to be done to every single record containing this customers' information. Otherwise, it would result in data inconsistency.
a. Insert Anomaly
b. Update Anomaly
C. Delete Anomaly
B. Update Anomaly
A customers information cannot be entered unless he/she has purchased goods/services from the company is?
a. Insert Anomaly
b. Update Anomaly
C. Delete Anomaly
A. Insert Anomaly
If we remove a sale then the customers information will be lost also.
a. Insert Anomaly
b. Update Anomaly
C. Delete Anomaly
C. Delete Anomaly
TRUE/FALSE?
A primary key can consist of multiple fields?
True
TRUE/FALSE?
A specific value of primary key can identify multiple instances?
False- once you get down need to identify
TRUE/FALSE?
A table can have multiple non-key attributes?
True- contact info, DOB, email, economic parameters)
TRUE/FALSE?
A table can have multiple foreign keys?
True-Ex.Sales can be linked to customer and inventory (Could even have ZERO)
A relational database logical model consists of ___&___?
Entities and Relationships.
Entities- "sales" and "customers"
Relationship- is "made to"
____ of a relationship represent Business rules for how many times an instance of entity A has an association with the instances in entity B.
Cardinalities
If a relationship has a ( ,N) and ( ,N) relationship you need to?
-Create another table
-Combine the names of the 2 tables with an underscore
-Use the combo of the two related entities as the new primary key -aka COMPOSITE KEY
To determine the foreign keys for a table you need to?
- post the primary key of table B [the one with ( ,N)] to table A ( ,1) as a foreign key
What is querying?
We ask questions about data in the database and design queries to manipulate and combine data in different ways
Two ways to develop queries?
Structural Query Language- where user enters commands according to pre-defined syntax
AND
Query by Example- user starts with a sample of the table(s) columns and marks the fields he wants to include in the answer- downside-have to do step by step-multiple queries
In a Query by Example, mathematically combine values from different fields for each row is called?
Horizontally calculations
(Do before vertically integrate and can't do in the same query)
In a Query by Example, summarizing data with a field(column)?
Vertically aggregating
(in access SUM)
Things that the organization acquires and uses and have economic values?
a. Events
b. Agents
c. Resources
c. Resources
ex.cashing and inventory
Various business activities about which management wants to collect information for planning or control purposes?
a. Events
b. Agents
c. Resources
a. Events
ex. sales and purchases
People and organizations who participate in events and about whom information is desired for planning, control, and evaluation purposes?
a. Events
b. Agents
c. Resources
b. Agents
ex. employees and vendors