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Understanding Functional Dependencies in Project Management Data

This project focuses on analyzing functional dependencies within project management data, including attributes like project name, budget, customer information, employee details, and machine specifics. It highlights key relationships based on Armstrong's Axioms, demonstrating how dependencies influence data retrieval and integrity. The purpose is to clarify how certain attributes relate to one another and ensure that the database structure reliably supports business needs, optimizing data consistency and accuracy for project management tasks.

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Understanding Functional Dependencies in Project Management Data

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  1. Functional Dependencies Quiz

  2. Project Relation Attributes • project name – pname • start date – start • budget • customer name – cname • customer phone – cphone • customer email – cemail • employee SIN – sin • employee first name – fname • employee last name – lname • employee category - cat (employee's occupation, e.g. welder, electrician) • employee rating – rank (a measure of seniority, a senior electrician might have a rank of 3) • employee hourly rate – rate (charged to customers) • machine ID – mid • machine description – desc • machine model – model • machine weight – weight • machine size – size • machine cost – cost • hours worked on a project by an employee - hours

  3. Functional Dependencies • pname • start • budget • cname • cphone • cemail • sin • fname • lname • cat • rank • rate • mid • desc • model • weight • size • cost • hours • pname, cnamestart, budget (one start date and budget) • cname cphone, cemail(a customer has one phone and email) • pname cname(projects are for only one customer) • sin, pname hours (number of hours an employee works on a project) • sin  fname, lname(a customer has one first and one last name) • sin, fname, lname cat, rank, rate (an employee has a categoty, rank and rate) • cat, rank  rate (the rate is derived from category and rank) • mid  desc(each machine has a description) • mid  model, cost (a machine is of a model, and has a cost) • mid, model  weight, size (a machine of a model type has a weight and size) • model  weight, size (weight and size are the same for machines of a model) • mid  pname(machines are only assigned to one project)

  4. Armstrong's Axioms • pname • start • budget • cname • cphone • cemail • sin • fname • lname • cat • rank • rate • mid • desc • model • weight • size • cost • hours • pname, cnamestart, budget • cname cphone, cemail • pname cname • sin, pname hours • sin  fname, lname • sin, fname, lname cat, rank, rate • cat, rank  rate • mid  desc • mid  model, cost • mid, model  weight, size • model  weight, size • mid  pname Is mid weight implied by F? Reflexivity – if XY, then XY Augmentation – if XY, then XZYZ Transitivity – if XY, and YZ then XZ Union – if XY and XZ, then XXZ Decomposition – if XYZ, then XY and XZ Pseudotransitivity – if XY and WYZ, then XWZ

  5. Armstrong's Axioms • pname • start • budget • cname • cphone • cemail • sin • fname • lname • cat • rank • rate • mid • desc • model • weight • size • cost • hours • pname, cnamestart, budget • cname cphone, cemail • pname cname • sin, pname hours • sin  fname, lname • sin, fname, lname cat, rank, rate • cat, rank  rate • mid  desc • mid  model, cost • mid, model  weight, size • model  weight, size • mid  pname Is mid sin implied by F? Reflexivity – if XY, then XY Augmentation – if XY, then XZYZ Transitivity – if XY, and YZ then XZ Union – if XY and XZ, then XXZ Decomposition – if XYZ, then XY and XZ Pseudotransitivity – if XY and WYZ, then XWZ

  6. Armstrong's Axioms • pname • start • budget • cname • cphone • cemail • sin • fname • lname • cat • rank • rate • mid • desc • model • weight • size • cost • hours • pname, cnamestart, budget • cname cphone, cemail • pname cname • sin, pname hours • sin  fname, lname • sin, fname, lname cat, rank, rate • cat, rank  rate • mid  desc • mid  model, cost • mid, model  weight, size • model  weight, size • mid  pname Is sin, mid fname, lname implied by F? Reflexivity – if XY, then XY Augmentation – if XY, then XZYZ Transitivity – if XY, and YZ then XZ Union – if XY and XZ, then XXZ Decomposition – if XYZ, then XY and XZ Pseudotransitivity – if XY and WYZ, then XWZ

  7. Armstrong's Axioms • pname • start • budget • cname • cphone • cemail • sin • fname • lname • cat • rank • rate • mid • desc • model • weight • size • cost • hours • pname, cnamestart, budget • cname cphone, cemail • pname cname • sin, pname hours • sin  fname, lname • sin, fname, lname cat, rank, rate • cat, rank  rate • mid  desc • mid  model, cost • mid, model  weight, size • model  weight, size • mid  pname Is sin, mid hours implied by F? Reflexivity – if XY, then XY Augmentation – if XY, then XZYZ Transitivity – if XY, and YZ then XZ Union – if XY and XZ, then XXZ Decomposition – if XYZ, then XY and XZ Pseudotransitivity – if XY and WYZ, then XWZ

  8. Attribute Closure • pname • start • budget • cname • cphone • cemail • sin • fname • lname • cat • rank • rate • mid • desc • model • weight • size • cost • hours • pname, cnamestart, budget • cname cphone, cemail • pname cname • sin, pname hours • sin  fname, lname • sin, fname, lname cat, rank, rate • cat, rank  rate • mid  desc • mid  model, cost • mid, model  weight, size • model  weight, size • mid  pname Compute the attribute closure of {sin, mid} Is {sin, mid} a superkey? Compute the canonical cover of F

  9. BCNF and Third Normal Form • pname • start • budget • cname • cphone • cemail • sin • fname • lname • cat • rank • rate • mid • desc • model • weight • size • cost • hours • pname, cnamestart, budget • cname cphone, cemail • pname cname • sin, pname hours • sin  fname, lname • sin, fname, lname cat, rank, rate • cat, rank  rate • mid  desc • mid  model, cost • mid, model  weight, size • model  weight, size • mid  pname Is machine = {mid, model, cost, weight, size} in BCNF? 3NF?

  10. BCNF and Third Normal Form • pname • start • budget • cname • cphone • cemail • sin • fname • lname • cat • rank • rate • mid • desc • model • weight • size • cost • hours • pname, cnamestart, budget • cname cphone, cemail • pname cname • sin, pname hours • sin  fname, lname • sin, fname, lname cat, rank, rate • cat, rank  rate • mid  desc • mid  model, cost • mid, model  weight, size • model  weight, size • mid  pname Is company = {cname, cphone, cemail} in BCNF? 3NF?

  11. FBCNF and Third Normal Form • pname • start • budget • cname • cphone • cemail • sin • fname • lname • cat • rank • rate • mid • desc • model • weight • size • cost • hours • pname, cnamestart, budget • cname cphone, cemail • pname cname • sin, pname hours • sin  fname, lname • sin, fname, lname cat, rank, rate • cat, rank  rate • mid  desc • mid  model, cost • mid, model  weight, size • model  weight, size • mid  pname Is works = {sin, pname, mid, hours} in BCNF? 3NF?

  12. Database Characteristics • pname • start • budget • cname • cphone • cemail • sin • fname • lname • cat • rank • rate • mid • desc • model • weight • size • cost • hours • pname, cnamestart, budget • cname cphone, cemail • pname cname • sin, pname hours • sin  fname, lname • sin, fname, lname cat, rank, rate • cat, rank  rate • mid  desc • mid  model, cost • mid, model  weight, size • model  weight, size • mid  pname Consider the set of relation schema: machine = {mid, cost, mid, hours}, model = {model, cost, weight} Do the schemas form a lossless join? Are they dependency preserving?

  13. Database Characteristics • pname • start • budget • cname • cphone • cemail • sin • fname • lname • cat • rank • rate • mid • desc • model • weight • size • cost • hours • pname, cnamestart, budget • cname cphone, cemail • pname cname • sin, pname hours • sin  fname, lname • sin, fname, lname cat, rank, rate • cat, rank  rate • mid  desc • mid  model, cost • mid, model  weight, size • model  weight, size • mid  pname Consider the set of relation schema: works = {sin, mid, hours}, machine_use= {mid, pname} Do the schemas form a lossless join? Are they dependency preserving?

  14. Decomposition • pname • start • budget • cname • cphone • cemail • sin • fname • lname • cat • rank • rate • mid • desc • model • weight • size • cost • hours • pname, cnamestart, budget • cname cphone, cemail • pname cname • sin, pname hours • sin  fname, lname • sin, fname, lname cat, rank, rate • cat, rank  rate • mid  desc • mid  model, cost • mid, model  weight, size • model  weight, size • mid  pname Is the project relation in 1NF or 2NF? Produce a 3NF, dependency preserving decomposition of the project relation

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