Exam (elaborations)
Relational Database Exam Study Questions Solved 100% Correct
- Course
- Institution
Relational Database Exam Study Questions Solved 100% Correct
[Show more]
Seller
Follow
Content preview
Relational Database Exam StudyQuestions Solved 100% Correct
update anomaly - ANSWER changes to existing data are not correctly recorded, due
to the multiple records with the same data attributes
insert anomaly - ANSWER unable to add a records to the database
delete anomaly - ANSWER removing a record also removes unintended data from
the database
update anomaly - ANSWER Suppose Alice Simpson changes her phone number. You
need to make the change in three places. If you fail to change it in all three places or
change it incorrectly in one place, then the records for Alice will be inconsistent
insert anomaly - ANSWER What happens if you have a new student to add, but
he hasn't signed up for any courses yet?
Or what if there is a new class to add, but there are no students enrolled in it yet?
In either case, the record will be partially blank.
delete anomaly - ANSWER If Ned withdraws from all his classes and you eliminate all
three of his rows from the table, then you will no longer have a record of Ned. If Ned is
planning to take classes next semester, then you probably didn't really want to delete all
records of him.
, Design requirements for relational data base - ANSWER 1. Every column must be
single valued.
2. Primary keys must contain data (Not
Null). Entity Integrity
3.Foreign Keys must contain the same data as the primary key in another
table. Referential Integrity
4.All other attributes must identify a characteristic of the table identified by the primary
key.
Describe the DATA Hierarchy - ANSWER Field- Attributes about an entity
Record- Related group of fields
File- related group of records
Database- related group of a files
What are the advantages of Database Systems - ANSWER Data Integration- Combined
and accessible
Data Sharing-easily to access
Minimizing Redundancy & Data inconsistency- Eliminates same data
storage Data independence- data separate from programs
Cross functional analysis- Departments can be more easily combined
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller KenAli. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $12.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
80796 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now