1. Database Design
Conceptual database design
Shashwat Shriparv
dwivedishashwat@gmail.com
InfinitySoft

2. Phase 2
• Involves 2 parallel activities :
1. Conceptual schema design -
2. Transaction and application design-

3. Conceptual level
• It hides physical storage and
concentrates on describing entities
,data types ,relationships, constraints...
• Its conceptual schema describes the
structure of the whole database for a
community of users

4. Conceptual schema design
Independent of the data base
because:
1. Goal of the conceptual schema design is a
complete understanding of the database structure,
meaning , interrelationships, and constraints. Its
best achieved independent of DBMS because each
has its own rules and restrictions which can affect
conceptual schema design.
2. Conceptual schema is a very valuable description of
the database .Choice of DBMS and data decisions
should not affect conceptual schema .

5. Conceptual schema design
3. A good understanding of the conceptual
schema is crucial for the users and
developers. High level data model is better
than data models of individual DBMS
4. Diagrammatic representations are excellent
for communicating among users, designers
and analyst. since high level models use
better concepts they are preferred over
lower level data model.

6. Characteristics of data model
1. Expressiveness
2. Simplicity and understandability
3. Minimality (least basic concepts that are distinct
and non overlapping)
4. Diagrammatic representation
5. Formality (formal unambiguous specification of
data)

7. Approaches to conceptual schema design
1. Centralized approach :requirements
of different applications and user groups are
merged together. a single schema is
designed corresponding to the merged set
of requirements. Task is arduous and time
consuming .
DBA and staff accomplish the task.

8. Approaches to conceptual schema design
2. View integration approach : a
schema is designed for each user
group based only on its requirements
.we develop a high level schema for
each group and combine into a
GLOBAL CONCEPTUAL SCHEMA.
Again DBA and staff accomplish the task.

9. Strategies for schema design
1. Top down strategy :start a schema
containing high level abstractions and
then apply successive top – down
refinement.
2. Bottom up strategy :start a schema
containing basic abstractions and then
combine or add these abstractions .

10. Strategies for schema design
3. Inside out strategy : special case of
bottom up where attention is focused
on a central set of concepts that are
most evident. Modeling then spreads
outwards by considering new concepts
in the vicinity of existing ones .
4. Mixed strategy :requirements
partitioned according to T D and part
of schema designed according to B U.

11. Course offering
Course # Sec # semester instructor
course instructorOffered by
name
Course# Sec#
semester
(1,N)(1,1)

12. faculty
student
faculty
student
advises Committee
chair of

13. Shashwat Shriparv
dwivedishashwat@gmail.com
InfinitySoft