Database Modeling And Normalization: Imagine That You
Database Modeling And Normalization W5imagine That You
Imagine that you work for a consulting firm that offers information technology and database services. Part of its core services is to optimize and offer streamlined solutions for efficiency. In this scenario, your firm has been awarded a contract to implement a new personnel system for a government agency. This government agency has requested an optimized data repository for its system which will enable the management staff to perform essential human resources (HR) duties along with the capability to produce ad hoc reporting features for various departments. They look forward to holding data that will allow them to perform HR core functions such as hiring, promotions, policy enforcement, benefits management, and training.
Using this scenario, write a 3–4 page paper in which you: Determine the steps in the development of an effective Entity Relationship Model (ERM) Diagram and determine the possible iterative steps/factors that one must consider in this process with consideration of the HR core functions and responsibilities of the client. Analyze the risks that can occur if any of the developmental or iterative steps of creating an ERM Diagram are not performed. Select and rank at least 5 entities that would be required for the development of the data repositories. Specify the components that would be required to hold time-variant data for policy enforcement and training management. Diagram a possible 1QM solution that will hold salary history data, job history, and training history for each employee through the use of graphical tools.
Note: The graphically depicted solution is not included in the required page length. Plan each step of the normalization process to ensure the 3NF level of normalization using the selected 5 entities of the personnel database solution. Document each step of the process and justify your assumptions in the process. Diagram at least 5 possible entities that will be required to sustain a personnel solution. The diagram should include the following: Dependency diagrams. Multivalued dependencies. Note: The graphically depicted solution is not included in the required...
Paper For Above instruction
The development of an effective Entity Relationship Model (ERM) diagram is a fundamental step in designing a robust and efficient personnel database system for a government agency. An ERM provides a conceptual blueprint that facilitates understanding of data entities, their attributes, and relationships, which directly influences the integrity, scalability, and usability of the database system. The process involves several iterative steps, each crucial for refining the model to accurately represent real-world HR processes while mitigating potential risks.
Steps in Developing an Effective ERM Diagram
- Requirements Gathering: Initial phase involves collecting detailed requirements from stakeholders, including HR managers, IT staff, and policy enforcers. Understanding core functions such as hiring, promotions, policy enforcement, benefits, and training is essential to identify necessary entities and attributes.
- Identify Entities and Relationships: Listing potential entities (e.g., Employee, Department, Job, Training, Benefits) based on requirements. Relationships such as "works for," "inherits position," or "attends training" are established.
- Define Attributes: For each entity, define key attributes, ensuring that they capture essential data points like Employee ID, Name, Hire Date, Training Completion Date, etc.
- Establish Primary Keys and Foreign Keys: Assign unique identifiers and relate entities via foreign keys to maintain referential integrity.
- Iterative Refinement: Continually review and refine the diagram by validating against real-world scenarios, adjusting relationships, and attributes as needed to ensure completeness and accuracy.
Considerations during these iterative steps include checking for redundancy, ensuring normalization, and accommodating future reporting needs. For example, including time-variant data such as policy enforcement dates or training periods necessitates special components to track history effectively.
Risks of Omitting Developmental or Iterative Steps
If these steps are skipped or inadequately performed, several risks arise. Poorly defined relationships may lead to data inconsistency, redundancy, and difficulty in maintenance. For example, neglecting to identify time-variant data components can result in unreliable historical reporting, affecting HR decision-making and compliance. Furthermore, not normalizing data to at least the third normal form (3NF) can cause anomalies during data updates, deletions, or insertions, compromising data integrity.
Key Entities for the Personnel Data Repository
- Employee: Core entity capturing personal and employment details.
- Job Position: Details about various positions held within the organization.
- Training Record: Tracks employee training programs attended.
- Benefits: Stores benefits assigned to employees, including eligibility and utilization.
- Policy Enforcement: Records policy adherence dates and enforcement actions.
Ranking these entities is based on their centrality to HR functions and data relationships, with Employee and Job Position being foundational, followed by Training Record, Benefits, and Policy Enforcement.
Components for Handling Time-Variant Data
To manage data that varies over time, such as policy enforcement and training history, temporal components like start and end dates are necessary. For example, a Policy Enforcement record might include enforcement date, policy type, and review status. Similarly, Training Records should document the training session date, completion status, and expiration date for recertifications. Using temporal tables or effective dates allows tracking historical changes and supports accurate reporting over time.
Designing a 1QM (One-Query Model) Solution for Employee Histories
The proposed 1QM solution involves creating a unified table structure that consolidates salary history, job history, and training history for each employee. This can be implemented through a denormalized table with fields such as EmployeeID, Salary, SalaryEffectiveDate, JobTitle, JobStartDate, TrainingProgram, CompletionDate. Relationships are managed through foreign keys, and the structure supports quick retrieval of historical data without complex joins.
The model also incorporates dependency diagrams illustrating functional dependencies such as EmployeeID → Salary, JobTitle, and TrainingProgram. Multivalued dependencies, such as multiple training sessions per employee, are managed via separate related tables or by employing multi-valued fields where appropriate, with due consideration for normalization standards.
Normalization Process for the Selected Entities
The normalization process begins by ensuring that each entity is in First Normal Form (1NF): eliminating repeating groups and ensuring atomicity of data fields. Next, Second Normal Form (2NF) is achieved by removing partial dependencies, ensuring that non-key attributes depend entirely on the primary key. Finally, to reach Third Normal Form (3NF), transitive dependencies are removed by ensuring that all non-key attributes are directly dependent only on the primary key.
For example, in the Employee entity, attributes like Department Name are moved to a separate Department entity to avoid dependency on the employee’s primary key, thereby ensuring 3NF compliance.
Dependency diagrams for each entity illustrate key dependencies, and multivalued dependencies are managed through linking tables (e.g., EmployeeTraining) to enforce normalization rules.
Assumptions made during this process include consistent attribute naming conventions, unique identifiers for entities, and the need to support historical data management. These assumptions underpin the normalization steps and entity relationships undertaken.
Conclusion
The process of developing an ERM diagram, considering iterative validation, and applying rigorous normalization ensures a comprehensive, scalable, and reliable HR database system. Proper attention to time-variant data components and dependency management is crucial for maintaining data integrity and supporting complex reporting requirements. Through careful planning and methodical normalization, the personnel system will support efficient HR functions, policy enforcement, and strategic decision-making for the government agency.
References
- Database Management Systems. Pearson Education.