Page 451 - Computer_Science_F5
P. 451
Computer Science (a) Conceptual data model a database or file format for a specific
system. It represents actual data storage
The conceptual data model offers a high-
within a DBMS, considering technical
level overview of organisational data,
and performance factors. Derived from
concentrating on business concepts,
conceptual and logical models, it includes
rules, and processes without addressing
FOR ONLINE READING ONLY
technical implementation details. It
and other DBMS features essential for
defines the structure of information entities, relationships, data types, keys,
needed for business operations, analytics, application development. Key aspects
and reporting, identifying essential include:
data and tracking business events and (i) Project-specific data representation
outcomes. Key characteristics include: (ii) Dependence on a particular DBMS
(i) Independence from hardware and version or technology
software specifications (iii) Cardinality and nullability in table
(ii) Comprehensive coverage of business relationships
concepts across the organisation (iv) Precise data type assignments
(iii) Design tailored for a business (v) Definition of keys, views, indexes,
audience and access profiles
(b) Logical data model The three data models, shown in Figure
The logical data model explore deeper 8.7, use Entity Relationship (ER)
into the company’s processes and their modeling to design a robust relational
interconnections, defining data structures database structure. Entities represent
such as entities, tables, and relationships. real-world objects with common
Its goal is to define data independently attributes, while relationships describe
of implementation, making it adaptable data sharing among these entities.
to various database systems and file
structures. Key characteristics include:
(i) Independence from specific DBMS
(ii) Capability to integrate with other Physical Model
logical data models Focuses on data design
and implementation of
the data model
(iii) Precise data attribute specifications
(iv) Adherence to normalization Explore deeper into processes, defines data
Logical Model
processes up to the Third Normal structure and how it is logically interconnected
Form (3NF)
Conceptual Model
Focuses on business concepts, rules and
(c) Physical Data Model processes
The physical data model details the Figure 8.7: Conceptual, logical and
design and implementation of data in physical data models
442
for Advanced Secondary Schools
Computer Science Form 5.indd 442 23/07/2024 12:34
