Thursday-solution_-1139956641

39 of 40 Let R = (A, B, C, D) be a relation schema with the FD's: A → B and B → A. R has how many superkeys? (Write your answer as an integer). write your answer here

Exercise 3.2.1: Consider a relation with schema R(A, B, C, D) and FD's AB → C, C → D, and D → A. a) What are all the nontrivial FD's that follow from the given FD's? You should restrict yourself to FD's with single attributes on the right side. b) What are all the keys of R? c) What are all the superkeys for R that are not keys?

THIS Question IS ASSOCIATED WITH CONCEPTS RELATED TO USE OF SEMANTIC OBJECT MODELS & TABLES IN DATABASES. Have a look at the following table # 3.1. Now try to convert this table into the corresponding Semantic object model diagram. Containing all objects, attributes and relationships.

Database Systems: Design and Application

c. For a schema R (A, B, C, D) bearing FDs F={A → B, B + c, C + D,D + A}, find if the decomposition of R into R1 (A, B, C) and R2 (B, c, D) is dependency preserving?

2NF and 3NF define key-based generic entities differently. Please illustrate.

Separate the main key-based definitions of 2NF and 3NF from the generic definitions using the sorting tool. Please provide a concrete illustration to back up your assertion.

3.5.4 Exercises for Section 3.5 Exercise 3.5.1: For each of the relation schemas and sets of FD's of Exer- cise 3.3.1: i) Indicate all the 3NF violations. ii) Decompose the relations, as necessary, into collections of relations that are in 3NF.

Based on the photo attatched, list each step in simple terms and explain each step in simpler terms

Consider the schema for a flight schedule database that keeps track of carriers (such as British Air), Airports (such as JFK Airport), and flights schedule (such as Flight 124 from Atlanta to London and its carrier is British Air).   Airport(AID,AName,ACity,ACountry) Carrier(CID,CName,CCity,CCountry) Flight(FromAirport,ToAirport,Date,CID)   Draw the initial query tree that corresponds to the following SQL query and then show how the query tree is optimized using heuristics:   Select F.AName as FName, T.AName as TName, CName From Airport as F, Airport as T, Flight, Carrier Where F.AID=Flight.FromAirport and T.AID=Flight.ToAirport and Flight.CID=Carrier.CID and Flight.Date=’1/1/2015’   You must show all the optimization steps and comment on each step.

Sort the generic definitions from the primary key-based definitions of 2NF and 3NF. Give a detailed example to support your claim.

The following are the objectives for the design of the logical schema:

Normalize the following schema, with given constraints, to 4NF. books(accessionno, isbn, title, author, publisher) users(userid, name, deptid, deptname) accessionno → isbn isbn → title isbn → publisher isbn →→ author userid → name userid → deptid deptid → deptname

23 of 40 Let R(A, B, C, D, E, F) be a relation with FD's: {D → CE, C → BDE, E → AD, AF → E, B → DF}. Which of the following statements is correct? Select one: O Ris in BCNF but not in 3NF. O Ris in 3NF but not in BCNF. O Ris not in 3NF and not in BCNF. O R is in 3NF and in BCNF.