COMP9315 Final Exam
COMP9315 Final Exam
Copyright By PowCoder代写 加微信 powcoder
The University of Wales
COMP9315 DBMS Implementation
Final Exam
DBMS Implementation
[Instructions] [Notes] [PostgreSQL] [C]
[Q1] [Q2] [Q3] [Q4] [Q5] [Q6] [Q7] [Q8]
Question 5 (5 marks)
Consider two tables R(x,y,z) and S(a,x,b)
with bR = 100
and bS = 20,
and a natural join on these two tables (via attribute x).
If we have a buffer pool with B = 20
buffers, then calculate how many pages would be read/written
when performing the join operation using the methods below.
Do not include the cost of writing the final result.
Block nested loop join, with R as outer table and S as inner.
Sort merge join, using intermediate files for sorting.
Do not assume any sort order on the original files.
Grace hash join, with R as outer table and S as inner.
Use buffers as appropriate for input, output and in-memory hash tables.
You can assume that all hash functions distribute tuples uniformly
and that all partitions of R will fit in the in-memory hash table.
Show all working.
Instructions:
Type your answer to this question into the file called q5.txt
Submit via: give cs9315 exam_q5 q5.txt
or via: Webcms3 > exams > Final Exam > Submit Q5 > Make Submission
End of Question
程序代写 CS代考 加微信: powcoder QQ: 1823890830 Email: powcoder@163.com