Q1:

Compare the following with the help of examples.

(a) Star schema and snowflake schema

(b) Data cleaning and data transformation

(c) Enterprise warehouse, data mart, and virtual warehouse

(d) OLAP and OLTP

Q2:

Explain three tiers of data warehouse architecture.

Which methods are used for efficient computations of data cubes.

Which algorithm is most appropriate to compute closed iceberg cubes efficiently?

Q3:

Consider the database containing transaction data as stated in the table below. Use Apriori algorithm to find frequent item sets where minimum support is 50% and minimum confidence is 50%.

Transactions	Item Set
I1	A,B,C
I2	A,C
I3	A,D
I4	B,E,F

Q4: Discuss candidate generation in Generalized Sequential Pattern (GSP) with the help of an example.