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COMP9311
Overview: Database Design 1
Data models:
◦ ER, Relational Data Model and their mapping
Relational Algebra:
◦ Be able to use relational algebra to answer question.
Database Languages:
◦ SQL (final exam: may need to write some simple SQL)
Relational Database Design:
◦ Functional Dependency
◦ Normal Forms
◦ Design Algorithms for 3NF and BCNF
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Overview: Database Design 2
Data Storage:
◦ Record Format,
◦ Buffer Management
Query Optimisation:
◦ Index
◦ Query Plan/Join Order Selection
Transaction Management:
◦ Concurrency Control
◦ Recovery
NoSQL:
◦ NoSQL Concept
◦ Different Data Model
◦ Key-Value, Document, Column-family, Graph
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Data Models
ER, Relational Data Model and their mapping
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Application E-R Relational DB
Entity-Relationship Model(cont)
1. Entity type: Group of object with the same properties
2. Entity: member of an entity type - analogous to an object.
3. Attribute: a property of object
4. Relationship: among objects
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Notmations (cont)
The notation used for ERDs is summarised in Elmasre/Navathe Figure
3.15.
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of a (strong) entity
of a weak entity
Relating to Weak Entities
Relational Data Model
In the relational model, everything is described using relations.
A relation can be thought of as a named table.
Each column of the table corresponds to a named attribute.
The set of allowed values for an attribute is called its domain.
Each row of the table is called a tuple of the relation.
N.B. There is no ordering of column or rows.