Question 1)
Information Management Prof.
June 18, 2020
Time available 2:00 hours
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1. Describe how ACID properties are affected by data distribution.
2. Illustrate the working of Vector clocks.
3. Consideringtheattachedschema,indicatethetimestampassociatedwitheachoperationofeachprocess.Fortheexercise, assume to adopt Vector clocks and that all the timestamps are initialized to 0. Operations are denoted with a tick on the line of the corresponding process.
To answer the question, indicate in the order the values of the vector clock associated with each operation for each process:
P1 : vc1, vc2,…, vc6 P2 : vc1, vc2,…, vc5 P3 : vc1, vc2,…, vc7
Question 2)
1. Describe OLTP and OLAP systems and clearly illustrate the differences between them.
2. Illustrate the multidimensional cube logical model. Provide an example of a cube.
3. Compute the answer that would be computed by a relational system for the query below, operating on the table on the left.
product color month price
nail polish
pencil red jan 5.00 pencil red feb 5.60 pencil brown jan 6.00 pencil cherry jan 6.20
red jan red feb pink jan cherry jan
10.00 select product, color, month, avg(prive) 11.00 from T
10.00 where color=”red” or color=”pink”
12.00 group by rollup (product, color, month)
red jan 6.00
Question 3)
1. Illustrating the concepts of support, confidence, and lift in frequent itmeset mining, reporting also the corresponding formula.
2. Computesupport,confidence,andliftoftheassociationrulesthatcanbeobtainedfromtheitemsetsinthelistbelow(the itemsets not in the list have frequency equal to 0).
Assume that the overall number of transactions is 50.
For the exercise, consider a minimum threshold for support min sup=0.35.
Association Rule
Confidence
To answer the question, draw a table with columns
Itemset Frequency Itemset
A 40 AB B 20 AC C 40 BC D 20 AD
Frequency Itemset Frequency
10 ABC 10 30 ACD 20 10
shop keep tracks, for each product, of the quantity ordered during
Date, Quantity, UnitPrice).
How would you use a MapReduce framework to identify, for each product, the overall quantity ordered for each product?
How would you define the map and the reduce functions? Illustrate your solution through an example with small tables.
Question 5) only for students who did not attend database course with Prof. Samarati
1. Illustrate the idempotency property for UNDO and REDO operations in log management.
2. Describe the difference between a checkpoint and a DUMP operation
3. Given the following schedule
w1(x) r1(x) w2(y) r3(x) w1(t) r2(y) r3(t) w3(x) w2(x) r2(t)
tell if it is VSR and/or CSR indicating (when existing) all the equivalent serial schedules.
Question 4)
Assume a distributed database for a franchising, where each
, ProductId, the year in a relation having schema ORDERS(Id
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