The document discusses key concepts in database development including: - The conceptual and physical levels of a database, with the conceptual being objects like tables and the physical being files on a hard disk. - Common data models like the entity relationship model and relational model that describe organizational data through entities, attributes, and relationships. - Key entities include objects an organization wants to track like students, employees, and departments.

1. Muhammad Umair
Oracle Database 11g Developer Track

2. › Database Creation
– Developers creates database conceptually, whereas
DBMS creates database physically.
– At conceptual level, database is consisting of a set of
objects (like tables) whereas at physical level database
is a set of files on hard disk
› Data Model
– A set of concepts used to describe data of a
organization at a higher level

3. › Entity Relationship Model (ER Model)
– A data model used to describe data of an organization
in the form of entities and their association
› Relational Model
– A data model used to describe data of an organization
in the form of relations
› Physical Data Model
– A data model that is at the lowest level and can be
converted to DBMS language directly

4. › Entity
– A group of objects having some characteristics about
which an organization wants to maintain data e.g.
– Students, Employee, Departments, Faculty, courses, lab,
– Library, degree etc.
– Entity can be person, place, thing, event or a concept.
› Entity Instance
– Single occurrence of a Entity

5. › Attribute
– An attribute is a characteristic of an entity about which
organization is interested
› Types of Attributes
– Composite Attribute
› An attribute that is divided into more attributes e.g.
› Date of birth can be divided into day, month, year.
› Qualification can be divided into degree-name, university,
passing year, %age

6. – Simple Attribute
› An attribute that can not divided into more attributes e.g.
› Gender (Male/Female), Salary
– Multi-valued Attributes
› An attribute that can hold more then one value for a single
entity instance e.g.
› Cell no, email-id, Experience, Qualification etc.
– Single-valued Attributes
› An attribute that can not hold more then one value for a single
entity instance e.g.
› Father name, Salary, Gender, Designation etc.

7. – Derived Attribute
› An attribute that is not necessary to be stored on hard disk
because its value can be calculated from some other attribute
e.g.
› Age can be calculated from date of birth, GPA can be
calculated from marks.
– Non-Derived Attribute
› An attribute that is necessary to be stored on hard disk because
its value can not be calculated from some other attribute e.g.
› Father Name etc.