A table ACCOUNTS in a database has 14 columns and 4 records. What is its degree if 2 more rows are added into the table? i) 14 ii) 16 iii) 8 iv) None of these
Answers
Answer:
Important Questions for Class 12 Computer Science (Python) – Database Concepts
Important Questions for Class 12 Computer Science (Python) – Database Concepts
Short Answer Type Questions-I
Question 1:
Observe the following PARTICIPANTS and EVENTS table cerefully and write the name of the RDBMS operation which will be used to produce the output as shown in RESULT? Also, find the Degree and Cardinality of the RESULT.
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important-questions-for-class-12-computer-science-python-database-concepts-2i
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Answer:
Cartesian Product
Degree — 4
Cardinality = 6
Question 2:
Define degree and cardinality. Also, Based upon given table write degree and cardinality.
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Answer:
Degree is the number of attributes or columns present in a table.
Cardinality is the number of tuples or rows present in a table.
Patients Degree = 4
Cardinality = 5
Question 3:
Observe the following table and answer the parts (i) and (ii):
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In the above table, can we have Qty as primary key.
What is the cardinality and degree of the above table?
Answer:
We cannot use Qty as primary key because there is a duplication of values and primary key value cannot be duplicate.
Degree =4
Cardinality = 5
Question 4:
Explain the concept of union between two tables, with the help of appropriate example.
Answer:
The union operation denoted by ‘U’ combines two or more relations. The resultant of union operation contain tuples that are in either of the table or in both tables.
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Question 5:
Observe the following STUDENTS and EVENTS tables carefully and write the name of the RDBMS operation which will be used to produce the output as shown in LIST table? Also, find the degree and cardinality of the table.
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Answer:
Cartesian Product
Degree = 4
Cardinality = 6
Answer:
i) 14
Explanation:
Degree is No. of Columns.
2 Rows will be added to 4 records.
No change in columns.