1. What is OLAP?
a) Online Longitudinal Analytical Processing
b) Online Analytical Processing
c) Offline Analytical Process
d) Overlooked Analytical Platform
Answer: b) Online Analytical Processing
Explanation: OLAP is a technology that enables analysts to extract and view business data from different perspectives, facilitating multidimensional analysis of large volumes of data.
2. Which of the following OLAP operations involves the transformation of data from detailed to summarized views?
a) Drill-down
b) Roll-up
c) Slice
d) Dice
Answer: b) Roll-up
Explanation: Roll-up involves aggregating data along one or more dimensions, moving from a detailed level to a higher level of summarization.
3. Which OLAP query operation restricts data along one or more dimensions?
a) Drill-down
b) Roll-up
c) Slice
d) Dice
Answer: c) Slice
Explanation: Slicing involves selecting a single value along one or more dimensions, thereby restricting the data to a specific subset.
4. Which type of OLAP server stores pre-aggregated data in multidimensional cubes?
a) ROLAP
b) MOLAP
c) HOLAP
d) DOLAP
Answer: b) MOLAP
Explanation: Multidimensional OLAP (MOLAP) servers store data in multidimensional arrays (cubes), allowing for fast query performance due to pre-aggregation.
5. What does ROLAP stand for in the context of OLAP servers?
a) Relational Online Analytical Processing
b) Real-time Online Analytical Processing
c) Rational Online Analytical Processing
d) Reflective Online Analytical Processing
Answer: a) Relational Online Analytical Processing
Explanation: ROLAP servers operate directly on relational databases, utilizing SQL queries to perform OLAP operations.
6. Which OLAP operation allows users to view data at a more detailed level?
a) Drill-down
b) Roll-up
c) Slice
d) Dice
Answer: a) Drill-down
Explanation: Drill-down involves navigating from summarized data to detailed data by moving down through the hierarchy of one or more dimensions.
7. Which type of OLAP server combines the benefits of both ROLAP and MOLAP?
a) HOLAP
b) DOLAP
c) EOLAP
d) SOLAP
Answer: a) HOLAP
Explanation: Hybrid OLAP (HOLAP) servers store some data in multidimensional cubes (like MOLAP) and other data in relational tables (like ROLAP), offering a balance between performance and flexibility.
8. In OLAP, what does the term “Drill-across” refer to?
a) Navigating through different dimensions within the same hierarchy
b) Analyzing data from different OLAP cubes
c) Accessing data stored in different databases
d) Moving from one level of aggregation to another
Answer: b) Analyzing data from different OLAP cubes
Explanation: Drill-across involves performing analysis by accessing and combining data from multiple OLAP cubes, allowing for comprehensive cross-dimensional analysis.
9. What is the primary purpose of OLAP systems?
a) To facilitate real-time transaction processing
b) To optimize data storage in data warehouses
c) To support complex analytical and ad-hoc queries
d) To automate data cleansing processes
Answer: c) To support complex analytical and ad-hoc queries
Explanation: OLAP systems are designed to enable users to perform multidimensional analysis of data, allowing for flexible and in-depth exploration of business information.
10. Which of the following is a key consideration for the operational design of data warehouses related to security?
a) Data compression techniques
b) Load balancing algorithms
c) Access control mechanisms
d) Indexing strategies
Answer: c) Access control mechanisms
Explanation: Access control mechanisms are essential for ensuring that only authorized users can access and manipulate data within the data warehouse, thereby maintaining data security and integrity.