DBMS-Query Processing and Optimization Questions and Answers
DBMS Query Processing and Optimization is a crucial area of aptitude questions and answers with explanations for database exams and interviews. It focuses on how a DBMS translates SQL commands into executable steps, selects the best execution plan, and minimizes processing time. Concepts such as query parsing, optimization algorithms, and indexing are central to improving database performance. Companies like TCS, Infosys, and Cognizant often test these fundamentals in placement exams. Practicing database aptitude test practice online helps students develop a strong foundation in performance tuning and query optimization strategies.
DBMS-Query Processing and Optimization
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15 questions
1. During the query processing the syntax of the query is checked by
- parser
- compiler
- syntax checker
- none of these
2. A query execution strategy is evaluated by
- access or execution plan
- query tree
- database catalog
- none of these
3. The first phase of query processing is
- decomposition
- restructuring
- analysis
- none of these
4. In which phase of the query processing is the query lexically nd syntactically analysed using prsers to find out any syntax errors ?
- Normalization
- semantic analysis
- analysis
- all of these
5. Which of the following represents the results of a query in a query tree ?
- root node
- leaf node
- intermediate node
- none of these
6. Which of the following represents the result of a query in a query tree ?
- root node
- leaf node
- intermediate node
- none of these
7. In which of the query processing are the queries that are incorrectly formulated or are contradictory are rejected ?
- simplification
- semantic analysis
- analysis.
- none of these
8. The objective of query simplifier is
- transformation of the query to a semantically equivalent and more efficient form.
- detection of redundant qualifications
- elimination of common sub-expressions.
- all of these.
9. The objective of query simplifier is
- transformation of the query to a semantically equivalent and more efficient form.
- detection of redundant qualifications.
- elimination of common sub-expressions
- all of these
10. Which of the following will produce and efficient execution strategy ?
- performing Projection operations as early as possible.
- performing Selection operations as early as possible
- computing common expressions only once
- all of these