Computers and Technology, 30.12.2021 14:00 timijebs

For the purpose of tuning your database that has begun to slow down for some queries, you are looking for the best plan to execute the following queries on the relation described below: The relation you are dealing with is Employee with attributes ename, title, dname, and address; all are string fields of the same length. The ename attribute is a candidate key. The relation contains 10,000 pages. There are 10 buffer pages. (When answering the questions, make sure to describe the plan you have in mind.)
The first query is: SELECT E. title, E. ename FROM Employee E WHERE E. title=â€˜Administratorâ€™ Assume that only 10% of Employee tuples meet the selection condition.
a. Suppose that a clustered B+ tree index on ename is (the only index) available. What is the cost of the best plan? (5 marks)
Candidate key is ename Relation contains 10,000 pages, 10 buffer pages Therefore, the cost G is the best plan = 10,000
b. Suppose that a clustered B+ tree index on title is (the only index) available. What is the cost of the best plan? (5 marks)
c. Suppose that a clustered B+ tree index on dname is (the only index) available. What is the cost of the best plan? (5 marks)
d. Suppose that a clustered B+ tree index on is (the only index) available. What is the cost of the best plan? (5 marks)

Answers: 1

Show answers

Another question on Computers and Technology

Computers and Technology, 23.06.2019 04:00

Write a method that takes in an array of point2d objects, and then analyzes the dataset to find points that are close together. be sure to review the point2d api. in your method, if the distance between any pair of points is less than 10, display the distance and the (x,y)s of each point. for example, "the distance between (3,5) and (8,9) is 6.40312." the complete api for the point2d adt may be viewed at ~pf/sedgewick-wayne/algs4/documentation/point2d.html (links to an external site.)links to an external site.. try to write your program directly from the api - do not review the adt's source code.

Answers: 1

Answer

Computers and Technology, 23.06.2019 10:00

Whats three fourths of 15(this is supposed to be in math but i clicked too fast)

Answers: 1

Answer

Computers and Technology, 24.06.2019 07:30

Aproject involves many computing systems working together on disjointed task towards a single goal what form of computing would the project be using

Answers: 3

Answer

Computers and Technology, 24.06.2019 14:00

Which describes careers that have similar education requirements but different qualifications? product safety engineers and materials engineers industrial safety engineers and industrial health engineers quality control systems managers and inspectors industrial safety and health engineers and hand packers

Answers: 3

Answer

You know the right answer?

For the purpose of tuning your database that has begun to slow down for some queries, you are lookin...

Questions