Query Processing

Question 1
Marks : +2 | -2
Pass Ratio : 50%
A selection of the form satisfying the union of all records satisfying individual simple conditions is
Conjunctive selection
Disjunctive selection
Negation
None of the mentioned
Explanation:
A selection of the form satisfying the intersection of all records satisfying individual simple conditions is a disjunctive selection. This is a form of complex selection predicate.
Question 2
Marks : +2 | -2
Pass Ratio : 50%
The lowest level operator to access data in query processing is _______
File scan
File manipulation
File handling
File organization
Explanation:
The lowest level operator to access data in query processing is file scan. File scans are algorithms that locate and retrieve records that fulfill a selection criterion.
Question 3
Marks : +2 | -2
Pass Ratio : 50%
Search algorithms that use an index are referred to as _________
Index scans
Search scans
Primary scans
Equality scans
Explanation:
Search algorithms that use an index are called as index scans. We use the selection predicate to guide us through the choice of index to use in processing the query.
Question 4
Marks : +2 | -2
Pass Ratio : 50%
A relational algebra operation annotated with instructions on how to evaluate it is called _______
Evaluation algebra
Evaluation plan
Evaluation primitive
Evaluation engine
Explanation:
A relational algebra operation annotated with instructions on how to evaluate it is called Evaluation primitive. The evaluation primitive is the basis for evaluation of queries.
Question 5
Marks : +2 | -2
Pass Ratio : 50%
A selection of the form satisfying the intersection of all records satisfying individual simple conditions is
Conjunctive selection
Disjunctive selection
Negation
None of the mentioned
Explanation:
A selection of the form satisfying the intersection of all records satisfying individual simple conditions is a conjunctive selection. This is a form of complex selection predicate.
Question 6
Marks : +2 | -2
Pass Ratio : 50%
Which of the following can be implemented?
Conjunctive selection using one index
Conjunctive selection using composite index
Conjunctive selection by intersection of identifiers
All of the mentioned
Explanation:
Conjunctive selection using one index, conjunctive selection using composite index and conjunctive selection by intersection of identifiers can be implemented. These are A7, A8, A9 algorithms that use an index.
Question 7
Marks : +2 | -2
Pass Ratio : 50%
A sequence of primitive operations that can be used to evaluate a query are called as __________
Query evaluation algebra
Query evaluation plan
Query evaluation primitive
Query evaluation engine
Explanation:
A sequence of primitive operations that can be used to evaluate a query are called as Query evaluation plan. This is used by the query evaluation engine to process the queries.
Question 8
Marks : +2 | -2
Pass Ratio : 50%
A selection of the form giving all the records not satisfying simple individual conditions is ______
Conjunctive selection
Disjunctive selection
Negation
None of the mentioned
Explanation:
A selection of the form giving all the records not satisfying simple individual conditions is negation. This is a form of complex selection predicate.
Question 9
Marks : +2 | -2
Pass Ratio : 50%
Sorting of relations that do not fit in memory is called as _______
Internal sorting
External sorting
Overflow sorting
Overload sorting
Explanation:
Sorting of relations that do not fit in memory is called as external sorting.
Question 10
Marks : +2 | -2
Pass Ratio : 50%
Which of the following are steps in query processing?
Parsing and translation
Optimization
Evaluation
All of the mentioned
Explanation:
Parsing and translation, optimization, evaluation are all the basic steps to process a query.