Database Management System · Unit 5 · 5 hrs
The Relational Algebra and Relational Calculus
Exam-focused notes for The Relational Algebra and Relational Calculus (Database Management System, CSC265): what the TU syllabus asks and how it has actually been tested, with 5 solved past questions from this unit.
What this unit covers
- Unary Relational Operations: SELECT and PROJECT
- Relational Algebra Operations from Set Theory
- Binary Relational Operations: JOIN and DIVISION
- Additional Relational Operations
- the Tuple Relational Calculus
- the Domain Relational Calculus
the Tuple Relational Calculus
What is tuple relational calculus? Explain. [5]
Tuple Relational Calculus (TRC) is a non-procedural query language used to query relational databases. Unlike relational algebra (which is procedural), tuple relational calculus only describes what data is needed, not how to retrieve it. It provides the des...
Full solved answer →What is tuple realtion calculus ? Given the following schema, write tuple relational calculus for selecting name and address of employee who are working in a company having Cid=E01. Employee(Eid, Ename, Address, Cid) Company(Cid, CName) [5]
Schema: - Employee(Eid, Ename, Address, Cid) - Company(Cid, CName) Requirement: Retrieve Ename and Address of employees working in a company with Cid = E01. No numeric matrices or missing data; this is a conceptual/query question. --- Tuple Relational Calcu...
Full solved answer →Binary Relational Operations
Write short notes on: a. Natural join b. Shadow paging [5]
--- Natural Join is a binary relational operation that combines two relations based on their common attributes (columns that share the same name and same data type). - It is denoted by the join symbol (⋈) - The common attribute(s) must have the same name an...
Full solved answer →Retrieve the TName, and No_of_priod of teachers who teach in 'ABC' school using Relational Algebra.TEACHER (TID, TName, TAddress, TQualification), SCHOOL (SID, SName, SAddress, SPhone), SCHOOL_TEACHER (SID, TID, No_of_Period) [5]
Relation Attributes ------ TEACHER (TID, TName, TAddress, TQualification) SCHOOL (SID, SName, SAddress, SPhone) SCHOOLTEACHER (SID, TID, NoofPeriod) --- Apply the Selection (σ) operation to filter the school with name 'ABC': $$\sigma{SName = 'ABC'} (SCHOOL)...
Full solved answer →Explain the difference between 'Join' and 'Natural Join' of algebraic operations with example. [5]
A Join operation combines tuples from two relations based on a specified condition (called a join predicate). The condition is explicitly stated by the user and can involve any comparison operator (=, <, , <=, =, !=). - The joining attribute(s) need not hav...
Full solved answer →Make Unit 5 stick
Practice CSC265 with flashcards & quizzes