CO532 - Database Systems
What we need to know for the exam.
- Created by: Arti
- Created on: 24-04-13 00:15
View mindmap
- Database Systems
- Data Modelling
- CDM
- LDM
- 1. Construct CDM
- 2. Resolve *..* relationships
- 3. Resolve heirarchal relationships
- 4. Map CDM to relational Schema
- 5. add required constraints
- PDM
- ER Modelling
- Entity
- Attribute
- Keys
- PK
- CK
- Constraints
- Entity integrity
- Referential integrity
- Domain
- Keys
- Relationship
- Constraints
- Participation
- Disjoint or Overlapping
- Properties
- Degree
- Multiplicity
- Participation
- Cardinality
- Types
- 1..1
- 1..*
- *..*
- Constraints
- Properties
- Top-down
- informal, intuitive
- real world oriented
- can represent full semantics
- Abstraction
- Classification
- Aggregation
- Specialisation & Generalisation
- Constraints
- Disjoint or Overlapping
- Constraints
- Normalisation
- FD
- TD
- PD
- Process
- NFs
- 1NF
- 2NF
- 3NF
- Higher NFs
- Boyce - Codd NF (BCNF)
- 4NF
- 5NF
- Decompose relations
- Data redundancy
- Undesirable dependancies
- Reduces anomalies
- No info must be lost
- NFs
- Decomposition
- Lossless join
- Preserve tuples
- Dependancy preservation property
- Preserve constraints
- Lossless join
- Properties
- Bottom - Up
- Formal
- Database oriented
- ltd semantics only unless additional steps introd
- SQL
- Langauage
- CREATE TABLE
- DROP TABLE
- Specifies quesries
- SELECT
- INSERT
- UPSDATE
- DELETE
- VIEW
- Logical operators
- AND, OR , NOT, IN
- Pattern matching
- LIKE, %
- Range Searching
- BETWEEN
- sorting
- ORDER BY
- ASC, DESC
- NULL
- Rename
- AS
- Grouping objects
- GROUP BY
- HAVING
- Data type
- Character
- Text
- VARCHAR(n)
- CHAR(n)
- Number
- INTEGER
- FLOAT
- NUMERIC(p,s)
- Temporarl
- DATE
- TIME
- Logical
- BOOLEAN
- Character
- Integrity Constraints
- Mandatroy data
- Column/value constraints
- Entity integrity
- Referential integrity
- Enterprise constraints
- Aggregate functions
- COUNT, SUM, AVG, MIN, MAX
- Langauage
- Relational Model
- 3 aspects of data
- Mathematical concept
- Terminology
- Relation
- Attribute
- Tuple
- Relationship
- Domain
- Keys
- Candidate
- Alternate
- Primary
- Foreign
- Composite
- Database Constraints
- Integrity
- Entity
- Referential integrity
- Multiplicity
- Required data
- Domain
- Integrity
- Relational algebra
- Ristrict
- Project
- Cartisan product
- Union
- Difference
- Join
- Division
- Intersection
- Data Modelling
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