Consider the relations Courses1, Courses2,_Enrollmentand Students.Courseslcid enameAl CalculusLocationL1A2 Algebra L2A5 EnglishL3Student(sid, sname, age, level)Courses2cidA5B1B2b) Courses 1-Courses2nameEnglishL3HistoryL4Computing L5(1) Give the results of the following relationalalgebra expressions:a) Teid ( name="History' OR 'Computing (Courses2))c) Courses Courses2Classroomd) Courses1 Enrollmente) Enrollment / Teid (Courses1)Enrollmentsid cid101Al102A5103 Bl102Al102A2(2) Write the following query in Relational Algebra.a) Find the sids of students who have enrolled incourse Calculus.b) Find the names of students who have enrolled incourse Calculus._c) Find the names of students who have enrolled atleast one course.d) Find the names of students who have enrolled in_Calculus or Algebra.e) Find the sids of students who have enrolled in allcourses (both Courses1 and Courses2).

Write the following query in Relational Algebra. a) Find the sids of students who have enrolled in…

Consider the relations Courses1, Courses2, _Enrollment and Students. Courses cid ename Al Calculus A2 Algebra L2 A5 English L3 Location LI Student(sid, sname, age, level) Courses2 cid AS Bl B2 Classroom L3 L4 Computing LS b) Courses 1-Courses2 name English History (1) Give the results of the following relational _algebra expressions: a) Teid ( name='History' OR 'Computing (Courses2)) c) Courses Courses2 d) Courses1 Enrollment Enrollment sid cid 101 Al 102 A5 103 BI 102 Al 102 A2 e) Enrollment / Teid (Courses1)

Consider the relations Courses1, Courses2, _Enrollment and Students. Courses cid ename Al Calculus A2 Algebra L2 A5 English L3 Location LI Student(sid, sname, age, level) Courses2 cid AS Bl B2 Classroom L3 L4 Computing LS b) Courses 1-Courses2 name English History (1) Give the results of the following relational _algebra expressions: a) Teid ( name='History' OR 'Computing (Courses2)) c) Courses Courses2 d) Courses1 Enrollment Enrollment sid cid 101 Al 102 A5 103 BI 102 Al 102 A2 e) Enrollment / Teid (Courses1)

Principles of Information Systems (MindTap Course List)

12th Edition

ISBN:9781285867168

Author:Ralph Stair, George Reynolds

Publisher:Ralph Stair, George Reynolds

Chapter5: Database Systems And Applications

Section: Chapter Questions

Problem 4PSE: Using a graphics program, develop an entity-relationship diagram for a database application for an...

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Consider that a database contains the following relations PARENT(X, Y), and a relation BIRTH(X, B), where B is the birthdate of a person X. The following information is used for question (b), (c) that we have the following family tree
A database of application of wholesaler can be modelled by means of the relations price, in_stock and supplies. Price is a relation over products1…30, which models the association between prices and stock items. In_stock is a relation over productsN, which models the association between stock items and the current number in stock of product. Supplies is a relation over suppliersproducts which models the relation between a supplier and the product that is delivered by that supplier. If the current value of these relations are following:price = {(nut, 5), (bolt, 13), (screw, 3), (board, 25), (fastener, 23)}, in_stock = {(nut, 700), (bolt, 2200), (screw, 55), (board, 0), (fastener, 600)}, supplies = {(Thomas, nut), (Thomas, bolt), (Wilks, bolt), (Wilks, screw), (Wilks, board), (Wilks, fastener), (Rogers, board), (Rogers, fastener)}, then what is the value of the following expressions? i. {nut, bolt} priceii. dom(price 1…15).iii. rng(price 1…10).iv. dom(supplies; (in_stock {0})). v.…
I need help with the following Consider a STUDENT relation in a UNIVERSITY database with the followingattributes (Name, Ssn, Local_phone, Address, Cell_phone, Age, Gpa). Note thatthe cell phone may be from a different city and state (or province) from thelocal phone. A possible tuple of the relation is shown below:Name Ssn Local_phone Address Cell_phone Age GpaGeorge Shaw 123-45-6789 555-1234 123 Main St., 555-4321 19 3.75William Edwards Anytown, CA 94539a. Identify the critical missing information from the Local_phone andCell_phone attributes. (Hint: How do you call someone who lives in a dif ferent state or province?)b. Would you store this additional information in the Local_phone andCell_phone attributes or add new attributes to the schema for STUDENT?c. Consider the Name attribute. What are the advantages and disadvantagesof splitting this field from one attribute into three attributes (first name,middle name, and last name)?d. What general guideline would you recommend for…
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 onerecord per student-class pair such that the student is enrolled in the class. Level is atwo character code with 4 different values (example: Junior: A Level etc)Write the following queries in SQL. No duplicates should be printed in any of theanswers.i. Find the names of all Juniors (level = A Level) who are enrolled in a classtaught by Prof. Kwizeraii. ii. Find the names of all classes that either meet in room R128 or have five ormore Students enrolled.iii. Find the names of all students who are enrolled in two classes that meet atthe same time.
Suppose RR is a relation with attributes A1,A2,…,AnA1,A2,…,An. How many superkeys will RR have if a) The only candidate key is A1A1. b) The only candidate keys are A1A2A1A2 and A1A3A1A3.
Let relations r1(A, B, C) and r2(C, D, E) have the following properties: r1 has20,000 tuples, r2 has 45,000 tuples, 25 tuples of r1 fit on one block, and 30tuples of r2 fit on one block. Estimate the number of block transfers and seeksrequired using each of the following join strategies for r1 ⋈ r2: Block nested-loop join.
Suppose relations R(A,B) and S(B,C,D) are as follows
Suppose we have a relational database with five tables. table key Attributes S(sid, A) Sid T(tid, B) Tid U(uid, C) Uid R(sid, tid, D) sid, tid Q(tid, uid, E) tid, uid Here R implements a many-to-many relationship between the entities implemented with tables S and T, and Q implements a many-to-many relationship between the entities implemented with tables T and U. A. Write an SQL query that returns all records of the form sid, uid where sid is the key of an S- record and uid is the key of a U-record and these two records are related through the relations R and Q. Use SELECT and not SELECT DISTINCT in your query. B. Write an SQL query that returns records of the form A, C where the A-value is from an S- record and the C-value is from a U-record and these two records are related through the relations R and Q. Use SELECT and not SELECT DISTINCT in your query. C. Could one of your queries from parts (a) and (b) return more records than the other? If so, which one? Justify your answer. D.…
Suppose we have a relational database with five tables. table key Attributes S(sid, A) Sid T(tid, B) Tid U(uid, C) Uid R(sid, tid, D) sid, tid Q(tid, uid, E) tid, uid Here R implements a many-to-many relationship between the entities implemented with tables S and T, and Q implements a many-to-many relationship between the entities implemented with tables T and U. A. Write an SQL query that returns all records of the form sid, uid where sid is the key of an Srecord and uid is the key of a U-record and these two records are related through the relations R and Q. Use SELECT and not SELECT DISTINCT in your query. B. Write an SQL query that returns records of the form A, C where the A-value is from an Srecord and the C-value is from a U-record and these two records are related through the relations R and Q. Use SELECT and not SELECT DISTINCT in your query. C. Could one of your queries from parts (a) and (b) return…
Suppose we have a relational database with five tables.table key AttributesS(sid, A) SidT(tid, B) TidU(uid, C) UidR(sid, tid, D) sid, tidQ(tid, uid, E) tid, uidHere R implements a many-to-many relationship between the entities implemented with tables S and T, and Q implements a many-to-many relationship between the entities implemented with tables T and U.D. Suppose you replaced SELECT with SELECT DISTINCT in your queries from parts (a) and Could one of these modified queries return more records than the other? If so, which one? Justify your answer. E. Consider again your query from part (a). If pair sid, uid is returned by this query then there must exist at least one “path” that goes from from table S to table T (via relation R) and then from table T to table U (via relation Q). Note that there can be many such paths for a given pair sid, uid. Write an SQL query that returns records of the form tid, total where…
Computer Science Given the relation R (A, B, C, D, E, F, G) and the set of functional dependencies: F= {BCD → A, BC → E, A → F, F→G, C→D, A→G}, a) Decompose R into 3NF. Show the different steps. b) Is this decomposition also in BCNF? Why or why not?