Essay Sample on Database Modelling and Normalization

Introduction

In the creation of a database, modeling and normalization are critical aspects. According to Teorey, Lightstone, Nadeau, and Jagadish (2011), normalization entails the process of systematically breaking logical data tables into more straightforward data while modeling revolves around the creation of a data model. This paper will first determine the various steps in the development of an Entity Relationship Model (ERM) along with the possible iterative factors that need consideration in the HR core functions. Also, the paper will analyze what occurs if any of the ERM diagram steps are not performed. Next, I will deliver a preference of the entities needed for the development of the information repositories along with an explanation of the time variant and various components of this type of data. Later on, I will deliver a diagram of a possible 1: M solution meant to hold job history, salary history data, and training for each employee and provide an explanation of each of the normalization steps to maintain the 3NF level of normalization utilizing the selected entities. The diagrams required to sustain a personnel solution include multivalued dependencies and dependency diagrams.

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Entity-Relationship Model Development Steps, Diagram, HR Considerations and Responsibilities of the Client

The Entity-Relationship Model or Diagram is a conceptual way of depicting the relationship between entities. Within the Entity-Relationship Model, it accommodates components (such as entity, attribute, and cardinality. Entity cold includes a location, an individual or anything that can store data, while cardinality represents the constraints in the ERD, and the attribute representing the characteristics of the entity (Teorey et al., 2011). However, the steps in the development of a useful Entity-Relationship Model include;

Identify the entities - it involves the creation of boxes for each entity concept that is deemed relevant to the HR model.

Determining the relationship - it involves the modeling of the relationships between the entities by drawing lines that connect any related entities and labeling of the connection through the use of numeric notations.

Determine the type of the relationship - it involves the identification of the relevant attributes with the entities by focusing on the appropriate characteristics.

Reviewing of the Entity - Relationship Model with the technical managers and other involved stakeholders and repeating until the domain is accurately represented.

Possible Risk If Any Iterative Steps of Creating ERM Are Not Performed

The creation of an Entity-Relationship model is a process; therefore, it means that, if any of the developmental or iterative steps of creating the ERM diagram is not performed, various risks could occur. For instance, there could be a possible risk of incomplete formation of necessities or requirements of the Entity Relationship Diagram. Also, with the failure to performs any iterative steps, there is a potential risk of conflicting information on attributes (features of the entities) and their relationships (correlation among entities). Inability to meet the required objectives and failure in the definition of data are other possible risks that could occur.

Entities Required for the Development of the Data Repositories

In the various government companies, various entities would require for the development of the information or data repositories. In different ways, the entities play a significant role primarily in the implementation of the core program requirements. The vital entities include; management entity, department entity (such as security, hiring, and training), employee entity, customer entity, and salary entity.

Components Required to Hold Time-Variants Data for Policy Enforcement and Training Management

Time-Variant data involves data or information that contains the multi-value, the previous values as well as the current value in any given system (Tahaghoghi & Williams, 2006). In the involvement of the time-variant data with entities, various attributes may encompass the changed amount or value like employee address, contact information, among other details. Also, in the context that another variable must entail only a single value such as birth dates, the time-variant data contains two values. The first value of the time-variant data is the current entity with the present value attributes while the second value includes the entity with its data history, prior-value data or information, and the primary key.

Diagram for A Possible 1: M Solution Holding Salary History Data, Job History, And Training History for Each Employee

Normalization Process Steps to Ensure the 3NF Level of Normalization

The First Normal Form (1NF) includes the process of collecting every involved and related column with a given table. In the collection, the First Normal Form must maintain that there no repeated group in the provided tables. Moreover, it supports the implementation of the primary keys in their given location and ensuring that every column has unique value considering that there must no null amount or value.

The Second Normal Form (2NF) which is the second step of the normalization plays a significant role in the personnel database solution. The 2NF is based on the details of the First Normal Form whereby, both 1NF and 2NF table rely on the occurrence that all of the Second Normal Form nonprimes attributes are dependent on the details of the First Normal Form.

The Third Normal Form (3NF) in the third process in the normalization of a database and is built on the First Normal Form and the Second Normal Form. Within the formation of the 3NF, it derives that all columns reference in referenced data that do not rely on or are not dependent on the primary key should not be included. Furthermore, an additional way of putting this is that only the crucial foreign column is utilized in the referencing of another table requiring that no other column derived from the parent table should exist in the referenced table.

Conclusion

In conclusion, the model dependency diagram depicts on at least five possible entities that could be vital to ensure the sustenance of a personal solution (Czenky, 2010). In each of the given levels, it is critical to understand that that the ERM diagram delivers an explanation of the system database and is utilized in an attempt to understand its utilization in an efficient way aligned to a company's requirements.

References

Czenky, M. (2010). Normalization based on dependency diagram. Teaching Mathematics and Computer Science, 8(1), 121-132.

Tahaghoghi, S. M., & Williams, H. E. (2006). Learning MySQL: Get a Grasp on Your Data. " O'Reilly Media, Inc.."

Teorey, T. J., Lightstone, S. S., Nadeau, T., & Jagadish, H. V. (2011). Database modeling and design: logical design. Elsevier.