Exam (elaborations)
INF2603 EXAM PACK 2021 (SUMMARY< EXAMS< MEMO"S<ASSIGNMENTS)
- Institution
- University Of South Africa (Unisa)
- Book
- Database Systems
Exam pack for INF2603 for the year 2021
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
3 reviews
By: francobooysen • 2 year ago
By: slaskydani • 3 year ago
By: npritilall • 3 year ago
Content preview
INF2603 EXAM PACK 2021,INF2603 SUMMARY
2021
,Contents
Chapter 1: Database Systems ........................................................................................................................... 4
Types of databases ......................................................................................................................................... 4
Historical Roots: Files and File Systems ...................................................................................................... 4
Basic file terminology: ............................................................................................................................... 4
Structural and Data dependence:............................................................................................................ 5
Data Redundancy ....................................................................................................................................... 5
Database Systems .......................................................................................................................................... 5
The database system environment ......................................................................................................... 5
DBMS Functions ......................................................................................................................................... 6
Managing the DB System .......................................................................................................................... 6
Chapter 2: Data Models ..................................................................................................................................... 7
The Importance of Data Models .................................................................................................................. 7
Data Model Basic Building Blocks ................................................................................................................ 7
Business Rules ................................................................................................................................................. 7
Discovering Business Rules ....................................................................................................................... 7
The Evolution of Data Models ...................................................................................................................... 7
The Hierarchical Model ............................................................................................................................. 7
The Network Model ................................................................................................................................... 7
The Relational Model ................................................................................................................................ 7
The Entity Relationship Model ................................................................................................................. 8
The Object-Orientated (OO) model......................................................................................................... 8
Degrees of data abstraction ......................................................................................................................... 9
Chapter 3: The Relational Database Model .................................................................................................. 10
A logical view of data ................................................................................................................................... 10
Tables and their characteristics ............................................................................................................. 10
Attributes and Domains .......................................................................................................................... 10
Degree of cardinality ............................................................................................................................... 11
Keys ................................................................................................................................................................ 11
Integrity Rules ............................................................................................................................................... 12
The data dictionary and the system catalogue ........................................................................................ 12
, Relationships within the relational database........................................................................................... 13
The 1:* Relationship ................................................................................................................................ 13
The 1:1 Relationship ................................................................................................................................ 13
The *:* Relationship ................................................................................................................................ 13
Data redundancy revisited .......................................................................................................................... 14
Indexes ........................................................................................................................................................... 14
Codd’s relational database rules ................................................................................................................ 14
Chapter 5: Entity relationship (ER) modelling .............................................................................................. 16
The entity relationship (ER) model ............................................................................................................ 16
Entities ....................................................................................................................................................... 16
Attributes .................................................................................................................................................. 16
Relationships............................................................................................................................................. 18
Multiplicity ................................................................................................................................................ 18
Existence dependence............................................................................................................................. 18
Relationship strength .............................................................................................................................. 18
Weak entities ............................................................................................................................................ 19
Relationship participation....................................................................................................................... 19
Relationship degree ................................................................................................................................. 19
Recursive relationships ........................................................................................................................... 20
Composite entities ................................................................................................................................... 20
Developing an ER diagram .......................................................................................................................... 21
Database design challenges: Conflicting goals......................................................................................... 21
Chapter 6: Advanced Data Modelling ............................................................................................................ 22
The extended entity relationship model (EERM) .................................................................................... 22
Entity supertypes and subtypes ............................................................................................................. 22
Specialisation hierarchy .......................................................................................................................... 22
Inheritance ................................................................................................................................................ 22
Subtype Discriminator ............................................................................................................................. 22
Disjoint and overlapping constraints .................................................................................................... 22
Completeness constraint ........................................................................................................................ 23
Specialisation and generalisation .......................................................................................................... 23
Composition and Aggregation................................................................................................................ 23
Entity Clustering ........................................................................................................................................... 24
Entity integrity: Selecting primary keys .................................................................................................... 24
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 EFT, 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 this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller StudyNotesUnisa2021. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R50,00. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
73918 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy summaries for 14 years now