The document discusses the need for databases and outlines some common problems with alternatives like spreadsheets. It then provides an overview of the database design process, including requirements modeling, building a conceptual data model with entities, attributes, and relationships, and then logical and physical database design. Key aspects of conceptual modeling are defined, such as identifying entity types and attributes, determining relationships and domains, and selecting primary keys. The modeling process is checked for redundancy and validated against user requirements.

1. Muhammad Umair
Oracle Database 11g Developer Track

2. › To solve a problem
– You have some data(information) of your client or your business you want
to create.
– There must be must be some data you want to store
– And this data could be anything about customers, employee, products,
dates, numeric from, document fine, images, audio/video etc.
› But you can already store data
– Write in a text file and type in your information
– Use spreadsheet
– If you got documents organize them in folder

3. › Many small business starts with spreadsheet
– And work continue like this for years
– And that might be causing no problem
› Just having data is not good enough reason to have
database
– Having data is not the problem

5. › Problems
– Size
– Ease of update
– Accuracy
– Security
– Redundancy
– Importance

6. › Size

7. › Ease of update

8. › Accuracy

9. › Security

10. › Redundancy

11. › Importance

12. › You might have all of these problems or some of these
problems
› These are the reason we need database
› These are the problems

13. › Requirements modeling (conceptual, pictures)
– Decide what entities
– should be part of the application
– and how they should be linked.

14. › Conceptual Model
– Merge the collective needs of all applications
– Determine what Entities are being used
› Some object about which information is to maintained
– What are the Attributes of those entities?
› Properties or characteristics of the entity
› What attributes uniquely identify the entity
– What are the Relationships between entities
› How the entities interact with each other?

15. Entities
Attributes
Relationships between entities
Product
address
buys

16. › Logical Model
– How is each entity and relationship represented in the Data
Model of the DBMS
› Hierarchic?
› Network?
› Relational?
› Object-Oriented?

17. › Determine user requirements
› Determine business rules
› Build conceptual data model
– outcome is an entity-relationship
diagram or similar
communication
tool
Enterprise
Modeling
Conceptual
Data Modeling
Logical
DB Design
Physical DB
Design/Creation
DB
Implementation
DB
Maintenance

18. › To build a conceptual data model of data
requirements of enterprise
– Model comprises entity types, relationship types,
attributes and attribute domains, primary and
alternate keys, and integrity constraints
› Step 1 Identify entity types
– To identify required entity types
– Typically nouns, noun phrases, major objects

20. › Step 2 Identify relationship types
– To identify important relationships that exist
between entity types
– Typically verbs, verb phrases
– Determine multiplicity constraints

23. › Step 3 Identify and associate attributes with
entity or relationship types
– To associate attributes with appropriate entity or
relationship types and document details of each
attribute
– Determine information required
› Step 4 Determine attribute domains
– To determine domains for attributes in data model
and document details of each domain

25. › Step 5 Determine candidate, primary, and
alternate key attributes
– To identify candidate key(s) for each entity and if
there is more than one candidate key, to choose
one to be primary key and others as alternate keys
– Strong entity
› Primary key easily identifiable
– Weak entity
› Primary key not identifiable
› Need to map entity & relationship to owner entity to identify
primary key

27. › Step 6 Consider use of enhanced modeling
concepts (optional step)
– To consider use of enhanced modeling concepts, such as
specialization / generalization, aggregation

29. › Check model for redundancy
– To check for presence of any redundancy in model
and to remove any that does exist

32. › Step 8 Validate conceptual model against
user transactions
– To ensure that conceptual model supports required
transactions
› Describe transactions
› Use transaction pathways
› Example
– List the details of properties managed by a named
member of staff at the branch

33. › Step 9 Review conceptual data model with
user
– To review conceptual data model with user to
ensure that model is ‘true’ representation of data
requirements of enterprise