MCQOPTIONS
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MCQOPTIONS
This section includes 13 Mcqs, each offering curated multiple-choice questions to sharpen your Rdbms knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The process of replacing a nested query with a query with a join is known as _________ |
| A. | Correlation |
| B. | Decorrelation |
| C. | Cache handling |
| D. | Join replacement |
| Answer» C. Cache handling | |
| 2. |
What technique is used for the evaluation of a query with a nested sub query? |
| A. | Caching |
| B. | Decorrelated evaluation |
| C. | Correlated evaluation |
| D. | Time based evaluation |
| Answer» D. Time based evaluation | |
| 3. |
Caching and reuse of query plans is called as ________ |
| A. | Query caching |
| B. | Plan caching |
| C. | Plan memorizing |
| D. | None of the mentioned |
| Answer» C. Plan memorizing | |
| 4. |
WHAT_TECHNIQUE_IS_USED_FOR_THE_EVALUATION_OF_A_QUERY_WITH_A_NESTED_SUB_QUERY??$ |
| A. | Caching |
| B. | Decorrelated evaluation |
| C. | Correlated evaluation |
| D. | Time based evaluation |
| Answer» D. Time based evaluation | |
| 5. |
The process of replacing a nested query with a query with a join is known as _________$ |
| A. | Correlation |
| B. | Decorrelation |
| C. | Cache handling |
| D. | Join replacement |
| Answer» C. Cache handling | |
| 6. |
Caching and reuse of query plans is called as _______? |
| A. | Query caching |
| B. | Plan caching |
| C. | Plan memorizing |
| D. | None of the mentioned |
| Answer» C. Plan memorizing | |
| 7. |
The join orders where the right operand of each join is in one of the initial relations are called as ________ |
| A. | Right deep join orders |
| B. | Left deep join orders |
| C. | Outer join orders |
| D. | None of the mentioned |
| Answer» C. Outer join orders | |
| 8. |
Optimizers use __________ to reduce the cost of optimization. |
| A. | Analyzers |
| B. | Statistics |
| C. | Heuristics |
| D. | Caches |
| Answer» D. Caches | |
| 9. |
State true or false: Making multiple copies of the same sub-expressions must be avoided |
| A. | True |
| B. | False |
| Answer» B. False | |
| 10. |
The rule that allows transformation of a logical operation to a physical operation is called |
| A. | Logical equivalence rule |
| B. | Physical equivalence rule |
| C. | Memory equivalence rule |
| D. | None of the mentioned |
| Answer» C. Memory equivalence rule | |
| 11. |
A particular sort order is said to be _________ sort order if it could be useful for a later operation. |
| A. | Interesting |
| B. | Reusable |
| C. | Efficient |
| D. | Good |
| Answer» B. Reusable | |
| 12. |
What is the disadvantage of cost based optimizers? |
| A. | It is too expensive |
| B. | It is inefficient in producing results |
| C. | It does not perform the desired function |
| D. | None of the mentioned |
| Answer» B. It is inefficient in producing results | |
| 13. |
A ________ explores the space of all query evaluation plans that are equivalent to a given query. |
| A. | Cost based optimizer |
| B. | Space based optimizer |
| C. | Time based optimizer |
| D. | None of the mentioned |
| Answer» B. Space based optimizer | |