Express R S ((Left outer join) using a subset of the following relational algebra operations (Project, Select, Rename, Union. Intersection, Set Difference, Cartesian product, Join (conditional or natural)). Explain your assumptions, if any. We assume that attributes of S is denoted as ATTR(S), attributes of R is denoted as ATTR(R) and (ATTR(R)-ATTR(S) denotes a set of attributes in R that does not belong to S. We also use the notation Mal, a2, a3... an (NULL) to denote a relation M with attributes (al, a2, a3, ..an) with one tuple whose values are null for all attributes. For example M id, name (NULL) will be Id Null Name Null

Express R S ((Left outer join) using a subset of the following relational algebra operations (Project, Select, Rename, Union. Intersection, Set Difference, Cartesian product, Join (conditional or natural)). Explain your assumptions, if any. We assume that attributes of S is denoted as ATTR(S), attributes of R is denoted as ATTR(R) and (ATTR(R)-ATTR(S) denotes a set of attributes in R that does not belong to S. We also use the notation Mal, a2, a3... an (NULL) to denote a relation M with attributes (al, a2, a3, ..an) with one tuple whose values are null for all attributes. For example M id, name (NULL) will be Id Null Name Null

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

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Defined the relational algebra operations as follows: SELECT (p, R) is equivalent to σp(R) referring to a set tuples of relation R that conforms to predicate p. PROJECT(L, R) is equivalent to πL(R) referring to a relation that contains a vertical subset of R, extracting the values of specified attributes L and eliminating duplicates. JOIN (R, p, S) refers to a relation containing a combination of tuples of relations R and S that satisfy the join condition p. FULL_JOIN (R, p, S) refers to a relation containing the result of outer join between relations R and S that satisfy the join condition p LEFT_JOIN (R, p, S) refers to a relation containing the result of left outer join between relations R and S that satisfy the join condition p RIGHT_JOIN (R, p, S) refers to a relation containing the result of right outer join between relations R and S that satisfy the join condition p CROSS (R, S) refers to a relation containing the catesian product of relations R and S. UNION (R, S)…
Consider a database containing two relations: R(A,B,C) and S(D,E,F). For each of three (your choice) of the 12 rewriting rules for relational algebra expression, give an example pair of relational algebra expressions involving R and S such that the rule rewrites one expression to the other expression, and give another example pair to show the rewriting rule cannot be used since some of the conditions for the rule arenot satisfied
Given relations P and Q, both over attributes A and B, write a query in relational algebra under bag semantics that returns P if Q is empty and returns Q if Q is not empty.
The division operator of relational algebra, “÷”, is defined as follows. Let r(R)and s(S) be relations, and let S ⊆ R; that is, every attribute of schema S isalso in schema R. Given a tuple t, let t[S] denote the projection of tuple t onthe attributes in S. Then r ÷ s is a relation on schema R − S (that is, on theschema containing all attributes of schema R that are not in schema S). A tuplet is in r ÷ s if and only if both of two conditions hold:• t is in ΠR−S(r)• For every tuple ts in s, there is a tuple tr in r satisfying both of the following:a. tr[S] = ts[S]b. tr[R − S] = tGiven the above definition:a. Write a relational algebra expression using the division operator to findthe IDs of all students who have taken all Comp. Sci. courses. (Hint:project takes to just ID and course id, and generate the set of all Comp.Sci. course ids using a select expression, before doing the division.)b. Show how to write the above query in relational algebra, without usingdivision. (By doing so, you…
The division operator of relational algebra, “÷”, is defined as follows. Let r(R)and s(S) be relations, and let S ⊆ R; that is, every attribute of schema S isalso in schema R. Given a tuple t, let t[S] denote the projection of tuple t onthe attributes in S. Then r ÷ s is a relation on schema R − S (that is, on theschema containing all attributes of schema R that are not in schema S). A tuplet is in r ÷ s if and only if both of two conditions hold:• t is in ΠR−S(r)• For every tuple ts in s, there is a tuple tr in r satisfying both of the following:a. tr[S] = ts[S]b. tr[R − S] = tGiven the above definition:a. Write a relational algebra expression using the division operator to findthe IDs of all students who have taken all Comp. Sci. courses. (Hint:project takes to just ID and course_id, and generate the set of all Comp.Sci. course_ids using a select expression, before doing the division.)b. Show how to write the above query in relational algebra, without usingdivision. (By doing so, you…
Decompose the relations, as necessary, into collections of relations that are in BCNF. R(A,B,C,D) with FD’s AB->C,C->D,and D->A. Could you show step by step procedure for this with detailed explaination?
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Convert ERD into Relational Model - show referential integrity appropriately
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Consider the relation schema R (A, B, C, D) with all possible functional dependencies. For each of the following situations, identify the highest normal form for this relation R. A, C -> B, D C -> D A, C -> B, D B -> D A, C -> B, D
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Note: Please make sure that all the points/rules must be implemented.Draw the ERD Diagram to create relational model corresponding to the described Scenario. The loan office in a bank receives from various parties, requests to investigate the credit status of aCustomers. Each credit request is identified by a Request ID and is described by a Request Date andRequesting party Name. The loan office also received results of credit checks. A credit check is identifiedBy a credit check ID and is described by the credit check Date and the credit rating. The loan officeMatches credit requests with credit check results. A credit request may be recorded before its resultArrives; a particular credit result may be used in support of several credit requests. Draw ERD for thisSituation. Requirements:ER Diagram of system implemented in tool such as Sqlyog & Draw.io (Available online).