DBMS-Query Processing and Optimization
DBMS-Query Processing and Optimization
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