Database Normalization

I normalized a Database to the 3rth Normal Form. 

I was given a dataset in an Excel spreadsheet, that was unnormalized:

For First Normal Form I made sure there were no repetitive groupings in the data.

and no repetitive data within each cell.

For Second Normal Form I made sure that All columns depend on the Unique ID.

For Third Normal Form I made that there were no transitive dependencies in the data:

The conceptual ERD Looks like this:

For normalization I needed to remove repetitions in the data, so the most important part is that the employees have data history in the information I received, so one important Query that I needed to be made is:

• Write a Query that returns current and past jobs (including employee name, job title, department, manager name, start and end date for position) for employee any employee,

So i needed an employee_history table that could keep the information I needed for this query:

The logical ERD keeps a table for employee, normalizing its data, there is another for company locations, Education and Salaries.

This design achieves the query that I want and also keeps data integrity in the employee data.

The manager can also be grabbed from the employee table as a second connection to employee_history.

The data types for this Physical ERD are for PostgreSQL.