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Python数据库代写|W4111 – Introduction to Databases Sections 002

Python数据库代写|W4111 – Introduction to Databases Sections 002




  • The homework submission date/time is 2022-MAY-01 at 11:59 PM.
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Question 1: Explain why a sparse index must also be a clustering index.


Question 2: Briefly explain sparse, multi-level indexes and their benefits. Why can the outer index be sparse?


Question 3: Indexes can significantly improve performance? What are some disadvantages of having many indexes?


Question 4: Briefly compare the pros and cons of B+-Tree versus a Hash Index.


Question 5: Briefly explain the concepts of covering index/covered query.


Question 6: Briefly explain the three main steps/stages in query processing.


Question 8: Explain the role of equivalent queries in query optimization.


Question 9: Assume that the ON clause in a JOIN on tables A and B compares columns a1 with b1 and column a2 with b2. What two properties must the ON condition have for the optimizer to be able to use a Hash Join?


Question 10: What is index selectivity? How does it factor into query optimization for JOINs?