MCQOPTIONS
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MCQOPTIONS
This section includes 4 Mcqs, each offering curated multiple-choice questions to sharpen your Rdbms knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Choose the option that correctly explains in words, the function of the following relational algebra expression year 2009 (book borrow) |
| A. | tSelects all tuples from the Cartesian product of book and borrow |
| B. | tSelects all the tuples from the natural join of book and borrow wherever the year is lesser than 2009 |
| C. | tSelects all the tuples from the natural join of book and student wherever the year is greater than or equal to 2009 |
| D. | tSelects all tuples from the Cartesian product of book and borrow wherever the year is greater than or equal to 2009 |
| Answer» C. tSelects all the tuples from the natural join of book and student wherever the year is greater than or equal to 2009 | |
| 2. |
Statement 1: A tuple is a row in a relation Statement 2: Existence of multiple foreign keys in a same relation is possible |
| A. | tBoth the statements are true |
| B. | tStatement 1 is correct but Statement 2 is false |
| C. | tStatement 1 is false but Statement 2 is correct |
| D. | tBoth the statements are false |
| Answer» B. tStatement 1 is correct but Statement 2 is false | |
| 3. |
What does the x operator do in relational algebra? |
| A. | tOutput specified attributes from all rows of the input relation. Remove duplicate tuples from the output |
| B. | tOutput pairs of rows from the two input relations that have the same value on all attributes that have the same name |
| C. | tOutput all pairs of rows from the two input relations (regardless of whether or not they have the same values on common attributes) |
| D. | tReturns the rows of the input relation that satisfy the predicate |
| Answer» D. tReturns the rows of the input relation that satisfy the predicate | |
| 4. |
What action does operator perform in relational algebra |
| A. | tOutput specified attributes from all rows of the input relation and remove duplicate tuples from the output |
| B. | tOutputs pairs of rows from the two input relations that have the same value on all attributes that have the same name |
| C. | tOutput all pairs of rows from the two input relations (regardless of whether or not they have the same values on common attributes) |
| D. | tReturn rows of the input relation that satisfy the predicate |
| Answer» B. tOutputs pairs of rows from the two input relations that have the same value on all attributes that have the same name | |