CS614 – Data Warehousing MCQs (Spring 2008–2011)
Q1: The automated, prospective analyses offered by data mining move beyond the analysis of past events provided by respective tools typical of:
(A) OLTP
(B) OLAP
(C) Decision Support Systems
(D) None of these
Answer: (B) OLAP
Q2: As opposed to the outcome of classification, estimation deals with ___ valued outcome.
(A) Discrete
(B) Isolated
(C) Continuous
(D) Distinct
Answer: (C) Continuous
Q3: The goal of ideal parallel execution is to completely parallelize those parts of a computation that are not constrained by data dependencies. The ___ the portion of the program that must be executed sequentially, the greater the scalability of computation.
(A) Larger
(B) Smaller
(C) Unambiguous
(D) Superior
Answer: (B) Smaller
Q4: ___, if it fits into memory, costs only one disk I/O access to locate a record by given key.
(A) An inverted index
(B) A sparse index
(C) A dense index
(D) None of these
Answer: (C) A dense index
Q5: The goal of ___ is to look at as few blocks as possible to find the matching records.
(A) Indexing
(B) Partitioning
(C) Joining
(D) None of these
Answer: (A) Indexing
Q6: There are many variants of the traditional nested-loop join. If an index is exploited, it is called ___
(A) Naïve nested loop join
(B) Index nested loop join
(C) Temporary index nested loop join
(D) None of these
Answer: (B) Index nested loop join
Q7: The act of model building in data mining has been done long before the ___ of computers or data mining technology.
(A) Access
(B) Advent
(C) Ascent
(D) Avowal
Answer: (B) Advent
Q8: Data mining is a/an ___ approach, where browsing through data may reveal something previously unknown to the user.
(A) Non-Exploratory
(B) Exploratory
(C) Computer Science
(D) None of these
Answer: (B) Exploratory
Q9: Data mining evolved as a mechanism to cater the limitations of ___ systems to deal with massive datasets.
(A) OLTP
(B) OLAP
(C) DSS
(D) DWH
Answer: (A) OLTP
Q10: The need to synchronize data upon update is called:
(A) Data Manipulation
(B) Data Replication
(C) Data Coherency
(D) Data Imitation
Answer: (C) Data Coherency
Q11: Taken jointly, the extract programs or naturally evolving systems formed a spider web, also known as:
(A) Distributed Systems Architecture
(B) Legacy Systems Architecture
(C) Online Systems Architecture
(D) Intranet Systems Architecture
Answer: (B) Legacy Systems Architecture
Q12: For good decision making, data should be integrated across the organization to cross the LoB (Line of Business) from the ___ perspective.
(A) Owner’s
(B) Customer’s
(C) Decision Maker’s
(D) Employee’s
Answer: (C) Decision Maker’s
Q13: Node of a B-Tree is stored in memory block and traversing a B-Tree involves ___ page faults.
(A) O(n)
(B) O(n²)
(C) O(n lg n)
(D) O(log n)
Answer: (D) O(log n)
Q14: Which statement is true for De-Normalization?
(A) Redundant data is a performance liability at query time, but is a performance benefit at update time.
(B) Redundant data is a performance benefit at both query time and update time.
(C) Redundant data is a performance liability at both query and update time.
(D) Redundant data is a performance benefit at query time, but a performance liability at update time.
Answer: (D) Redundant data is a performance benefit at query time, but a performance liability at update time.
Q15: Pre-join technique is used to avoid:
(A) Run-time join
(B) Compile-time join
(C) Load-time join
(D) None of these
Answer: (A) Run-time join
Q16: Cube is a ___ entity containing values of a certain fact at a certain aggregation level.
(A) Logical
(B) Physical
(C) Analytical
(D) None of these
Answer: (A) Logical
Q17: The goal of star schema design is to simplify:
(A) Logical data model
(B) Physical data model
(C) Conceptual data model
(D) None of these
Answer: (A) Logical data model
Q18: Grain is the ___ level of data stored in the warehouse.
(A) Atomic
(B) Summarized
(C) Aggregated
(D) Cube
Answer: (A) Atomic
Q19: Transactional fact tables do not have records for events that do not occur. These are called:
(A) Not Recording Facts
(B) Fact-less Facts
(C) Null Facts
(D) None of these
Answer: (B) Fact-less Facts
Q20: A ___ dimension is a collection of random transactional codes, flags, and attributes unrelated to any particular dimension.
(A) Junk
(B) Time
(C) Parallel
(D) None of these
Answer: (A) Junk
Q21: During ETL, which strategy is least complex?
(A) One-to-One Scalar Transformation
(B) One-to-Many Element Transformation
(C) Many-to-Many Element Transformation
(D) Many-to-One Element Transformation
Answer: (A) One-to-One Scalar Transformation
Q22: Change Data Capture is a challenging issue in:
(A) Data Extraction
(B) Data Loading
(C) Data Transformation
(D) Data Cleansing
Answer: (A) Data Extraction
Q23: Rearranging, delivering, and ensuring data quality in a warehouse is called:
(A) Cleansing
(B) Cleaning
(C) Scrubbing
(D) All of these
Answer: (D) All of these
Q24: When performing objective assessments, pervasive functional forms are:
(A) Simple Ratio, Min or Max Operation, Weighted Average
(B) Only Complex Ratio, Min Operation, Max Operation
(C) Only Simple Ratio, Min or Max Operation
(D) Only Min or Max Operation, Weighted Average
Answer: (A) Simple Ratio, Min or Max Operation, Weighted Average
Q25: The input to the data warehouse can come from OLTP or transactional system but not from other third-party databases.
(A) True
(B) False
Answer: (B) False
Q26: Normalization affects performance.
(A) True
(B) False
Answer: (A) True
Q27: Collapsing tables can be done on ___ relationships.
(A) One-to-One
(B) Many-to-Many
(C) Both One-to-One and Many-to-Many
(D) None of these
Answer: (C) Both One-to-One and Many-to-Many
Q28: ___ breaks a table into multiple tables based upon common column values.
(A) Horizontal splitting
(B) Vertical splitting
Answer: (B) Vertical splitting
Q29: If w is the window size and n is the size of data set, complexity of merging phase in BSN method is:
(A) O(n)
(B) O(w)
(C) O(w n)
(D) O(w log n)
Answer: (C) O(w n)
Q30: NUMA stands for:
(A) Non-uniform Memory Access
(B) Non-updateable Memory Architecture
(C) New Universal Memory Architecture
(D) None of these
Answer: (A) Non-uniform Memory Access