Ch3_Relational Data Model

Define Normalization

• Process for restructuring tables into single table containing all information needed

• Process representing data relationship in the form of a table that consist of row and column

• Process for retrieving information from relational database using suitable operators

• Process for assigning attributes to entities to determine whether the chosen entities, attributes and primary keys are appropriate and suitable for the system

The following are purpose of normalization in database model EXCEPT:

• Minimize data redundancy

• Allows database to be expanded if new requirements needed

• Reduce security problems in database by concurrency control

• Ensure good database schema which is represented by accurate table structure

Identify the importance of normalization in database.

• To create relational tables

• To maintain anomalies and accuracy

• To reduce integrity and consistency of the data

• To minimize redundancy and eliminate anomalies

The following are types of anomalies EXCEPT …

• Insertion anomalies

• Deletion anomalies

• Duplication anomalies

• Modification anomalies

Identify the characteristic that the table is in First Normal Form (1NF).

• The primary key is defined in all tables

• Rows has different values from each other

• The table contains one or more repeating groups

• Each attribute contains one and only one atomic value

Functional dependency (FD) can be denoted as A --> B. Choose the CORRECT definition of FD.

• For any relation R, B is functionally dependent on A, if each value of A is associated with exactly one value of B

• For any relation R, A is functionally dependent on B, if each value of A is associated with exactly one value of B

• For any relation R, B is functionally dependent on A, if each value of A is associated with all value of B

• For any relation R, A is functionally dependent on B, if each value of A is associated with all value of B

The relational tables are in Second Normal Form if all the following are removed:

• Transitive dependency

• Functional dependency

• Full functional dependency

• Partial functional dependency

Referring to the given relational schema, chose the attributes that violate the second normal form (2NF) property.

Supplier (SupID, SupName, Phone, Address, productName)

• SupID

• SupName

• Address

• ProductName

Choose the type of entity that only exist in the database while it is dependent to another entity in the same database.

• Strong entity

• Weak entity

• Simple entitiy

• Derived entity

Choose the basic elements of Entity Relationship Diagram (ERD).

• Attributes, Relationship, Primary Key

• Attributes, Entity, Primary Key

• Attributes, Relationship, Entity

• Attributes, Records, Entity