Presentation is loading. Please wait.

Presentation is loading. Please wait.

Functional Dependencies Quiz. Project Relation Attributes project name – pname start date – start budget customer name – cname customer phone – cphone.

Similar presentations


Presentation on theme: "Functional Dependencies Quiz. Project Relation Attributes project name – pname start date – start budget customer name – cname customer phone – cphone."— Presentation transcript:

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 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 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 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 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? 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? 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


Download ppt "Functional Dependencies Quiz. Project Relation Attributes project name – pname start date – start budget customer name – cname customer phone – cphone."

Similar presentations


Ads by Google