subject

An n-way join performs consecutive n-1 joins among n tables. for each of the following 8-way joins, state how many join orders are possible and why (make sure to explain the reason). note ri ⋈ rj and rj ⋈ ri (switching around the order of two joined relations) are different join orders. in the join expressions below, ⋈ denotes an inner join, |⋈ denotes a left outer join, ⋈| denotes a right outer join, and |⋈| denotes a full outer join. hint: note commutativity of the different types of join operations.

a) r1 ⋈ r2 ⋈ r3 ⋈ r4 ⋈ r5 ⋈ r6 ⋈ r7 ⋈ r8

b) r1 ⋈ r2 ⋈ r3 |⋈ r4⋈ r5 ⋈ r6 ⋈ r7 ⋈ r8

c) r1 ⋈ r2 ⋈ r3 ⋈| r4⋈ r5 ⋈ r6 ⋈ r7 ⋈ r8

d) r1 ⋈ r2 ⋈ r3 |⋈| r4⋈ r5 ⋈ r6 ⋈ r7 ⋈ r8

ansver
Answers: 3

Another question on Computers and Technology

question
Computers and Technology, 23.06.2019 11:30
Which excel file extension stores automated steps for repetitive tasks?
Answers: 1
question
Computers and Technology, 23.06.2019 13:00
In excel - calculate the actual increase/decrease from first quarter to the second quarter then subtract subtract first quarter value from second quarter total then divide result by first quarter value
Answers: 1
question
Computers and Technology, 23.06.2019 16:00
Kenny works with an it company. his company is about to launch new software in the market. he has to ensure that this new software is functional and meets all of the quality standards set up at the planning stage. which job profile is kenny likely to have? kenny is likely to have the job profile of a blank .
Answers: 2
question
Computers and Technology, 24.06.2019 10:00
3. what do the terms multipotentialite, polymath, or scanner mean?
Answers: 2
You know the right answer?
An n-way join performs consecutive n-1 joins among n tables. for each of the following 8-way joins,...
Questions
question
History, 04.05.2020 22:49
question
Mathematics, 04.05.2020 22:49
question
Mathematics, 04.05.2020 22:49
question
Mathematics, 04.05.2020 22:49
question
Mathematics, 04.05.2020 22:49
question
Mathematics, 04.05.2020 22:49
question
Mathematics, 04.05.2020 22:49
Questions on the website: 13722367