Database-Management-System
October 4, 2023Database-Management-System
October 4, 2023UGC-NET DEC-2019 Part-2
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Question 20
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Which of the component module of DBMS does rearrangement and possible ordering of operations, eliminate redundancy in query and use efficient algorithms and indexes during the execution of a query?
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query compiler
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query optimizer
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Stored data manager
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Database processor
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Question 20 Explanation:
The query optimizer (called simply the optimizer) is built-in database software that determines the most efficient method for a SQL statement to access requested data. The optimizer choose the plan with the lowest cost among all considered candidate plans(the cost computation accounts for factors of query execution such as I/O, CPU, and communication).
It rearrange and does the possible ordering of operations, eliminate redundancy in query and use efficient algorithms and indexes during the execution of a query
It rearrange and does the possible ordering of operations, eliminate redundancy in query and use efficient algorithms and indexes during the execution of a query
Correct Answer: B
Question 20 Explanation:
The query optimizer (called simply the optimizer) is built-in database software that determines the most efficient method for a SQL statement to access requested data. The optimizer choose the plan with the lowest cost among all considered candidate plans(the cost computation accounts for factors of query execution such as I/O, CPU, and communication).
It rearrange and does the possible ordering of operations, eliminate redundancy in query and use efficient algorithms and indexes during the execution of a query
It rearrange and does the possible ordering of operations, eliminate redundancy in query and use efficient algorithms and indexes during the execution of a query