Part 2 Module Practice You Have Been Given A File That Conta
Part 2 Module Practiceyou Have Been Given A File That Contains The F
Part 2 : Module Practice: You have been given a file that contains the following fields relating to CD information. Using the steps of normalization, create a logical data model that represents this file in third normal form. The fields include the following: • Musical group name • Musicians in group • Date group was formed • Group’s agent • CD title 1 • CD title 2 • CD title 3 • CD length 1 • CD length 2 • CD length 3 The assumptions are as follows: • Musicians in group contains a list of the members of the people in the musical group. Musical groups can have more than one CD, so both group name and CD title are needed to uniquely identify a particular CD.
Paper For Above instruction
The task of transforming a file containing information about musical groups and their CDs into a normalized data model involves understanding the principles of database normalization, particularly up to the third normal form (3NF). This process aims to organize data efficiently, eliminate redundancy, and ensure data integrity.
Initially, the raw data include fields such as musical group name, musicians in the group, date the group was formed, group's agent, multiple CD titles, and their lengths. The challenge lies in restructuring this data—originally in a flat file format—into a relational model that adheres to the rules of normalization.
The first step is to identify the functional dependencies and group related data attributes to establish the first normal form (1NF). The raw data suggest that each record contains multiple CD titles and lengths, which violate 1NF, as each attribute must contain only atomic, indivisible values. To address this, the CD information should be stored in a separate related table, which allows multiple CDs per musical group without repeating group information.
Next, moving to the second normal form (2NF) requires removing partial dependency; this involves ensuring every non-key attribute depends fully on the primary key. Given that a combination of group name and CD title can uniquely identify a CD, we can designate this combined key as the primary key for the CD table. Attributes like CD length depend solely on the CD, not on the group, which justifies splitting CD-specific data into a separate entity.
Confirmation of the third normal form (3NF) involves eliminating transitive dependencies. For example, the group's agent and date of formation depend on the group but not on the CD. To comply with 3NF, these attributes should be stored in a separate 'Group' table, with the group's name as the primary key, linking to the CD table via this key.
Applying these steps results in a logical data model with at least two main tables:
1. Group Table:
- Group Name (Primary Key)
- Date Formed
- Group Agent
2. CD Table:
- Group Name (Foreign Key)
- CD Title (part of composite primary key)
- CD Length
In addition, to incorporate musicians, a many-to-many relationship exists because a group can have multiple musicians, and musicians can belong to multiple groups. Thus, an associative table—'Musicians in Group'—can be created:
3. Musicians Table:
- Musician ID (Primary Key)
- Musician Name
4. Group_Musicians Table:
- Group Name (Foreign Key)
- Musician ID (Foreign Key)
This structure ensures each piece of information is stored once, dependencies are minimized, and relationships accurately model the real-world associations.
In summary, the normalization process transforms the initial flat file into a relational schema comprising the above tables, satisfying 3NF by removing partial and transitive dependencies, thus providing an efficient, scalable, and integrity-maintaining data model for the CD and musical group information.