Relational Algebra DBMS UGC NET CSA
| Q7➡ | NTA UGC NET June 2021 Given the following STUDENT-COURSE scheme: STUDENT (Rollno, Name, Courseno) COURSE (Courseno, Coursename, Capacity), where Rollno is the primary key of relation STUDENT and Courseno is the primary key of relation COURSE. Attribute Coursename of COURSE takes unique values only. The number of records in COURSE and STUDENT tables are 3 and 5 respectively. Following relational algebra query is executed: R=STUDENT X COURSE Match List I with List II in context to the above problem statement.  Choose the correct answer from the options given below: |
| i ➥ A -I , B -III , C -IV , D – II |
| ii ➥ A -I , B -III , C -IV , D – II |
| iii ➥ A -I , B -III, C -II , D – IV |
| iv ➥ A -III , B -I , C -IV , D – II |
| Answer – IV Explanation: A. Degree of Table R: The number of Attributes/Column in a table is called Degree of Table.  Degree of Table R is 6. B. Cardinality of Table R: The number of Tuples/records in a table is called Cardinality of Table. Since, The number of records in COURSE and STUDENT tables are 3 and 5 respectively. Cardinality of Table = 3 x 5 = 15 records C. Foreign key of relation STUDENT: Courseno is the primary key of relation COURSE and Courseno is the Foreign key of relation STUDENT. Because Foreign key is an attribute which referred to primary key of another Table. C. Foreign key of relation COURSE: There is no Foreign key in a relation COURSE. So, Option(IV) is correct. |