Functional Dependency Set Closure (F+) Functional Dependency Set Closure of F is the set of all functional dependencies that are determined by it. Example of Functional Dependency Set Closure : Consider a relation R(ABC) having following functional dependencies : F = { A → B, B → C } To find the Functional Dependency Set closure of…

Relational Calculus Relational calculus is non procedural, it is a language for expressing what we want without expressing. Relational calculus has a variable. For tuple relational calculus, the variable ranges over the tuples of a relation. For domain relational calculus, the variables ranges over the values of the domain. Tuple Oriented Relational Calculus The basic…

Questions on Timestamp Ordering Question 1 : Which of the following TS order allow to execute the above schedule using BTSO (Basic Timestamp Ordering) Protocol ? R1(A); R2(B); W1(C); R3(B); R3(C); W2(B); W3(A) a) (T1,T2,T3) = (10,20,30) b) (T1,T2,T3) = (30,10,20) c) (T1,T2,T3) = (30,20,10) d) (T1,T2,T3) = (20,30,10) e) (T1,T2,T3) = (10,30,20) Solution :…

Questions Based on Relational Algebra (Gate Questions Included) -Part 2 Question 21: Consider the relation Student(name,sex, marks) where the primary key is shown underlined, pertaining to students in a class that has at least one boy and one girl. What does the following relational algebra expression produce? a) names of girl students with the highest…

Questions on Relational Algebra (Part 1) Consider the relations: Suppliers(SID, Sname, Rating) Parts(PID, Pname, Color) Catalog( SID, PID, Cost) Query 1: Retrieve SIDs of Suppliers whose rating > 10. Solution: Query 2: Retrieve SIDs of Suppliers who supplied red parts. Solution: Query 3: Retrieve Sname of Suppliers who supplied red parts. Solution: From optimization point of…

Questions Based on SQL – Part 6 Question 1 : Consider the following relations: Student(snum: integer, sname: string, major: string, level: string, age: integer) Class(name: string, meets at: string, room: string, fid: integer) Enrolled(snum: integer, cname: string) Faculty(fid: integer, fname: string, deptid: integer) The meaning of these relations is straightforward; for example, Enrolled has one…