Q#1: If there are N records in a table, then the selectivity of primary key column is
(A) 1/N
(B) N/2
(C) lg(N)
Answer: (A) 1/N
Q#2: ____ is one class of decision support environment.
(A) OLAP
(B) OLTP
(C) Data Cleansing
(D) ETL
Answer: (A) OLAP
Q#3: The users of data warehouse are
(A) Decision makers
(B) Knowledge workers
(C) Both Knowledge workers and Decision makers
Answer: (C) Both Knowledge workers and Decision makers
Q#4: The users of data warehouse are knowledge workers in other words they are ____ in the organization.
(A) Decision maker
(B) Manager
(C) Database Administrator
(D) DWH Analyst
Answer: (A) Decision maker
Q#5: Effects of de-normalization on database performance are
(A) Unpredictable
(B) Predictable
(C) Conventional
(D) Unsurprising
Answer: (A) Unpredictable
Q#6: OLAP is used for analytical process. For analytical processing we need
(A) Multi-level aggregates
(B) Record level access
(C) Data level access
(D) Row level access
Answer: (A) Multi-level aggregates
Q#7: Multidimensional databases typically use proprietary ____ format to store pre-summarized cube structures.
(A) File
(B) Application
(C) Aggregate
(D) Database
Answer: (A) File
Q#8: Normally selectivity of query in OLTP system is
(A) High
(B) Low
(C) Not measured
Answer: (A) High
Q#9: Normally selectivity of query in data warehouse is
(A) High
(B) Low
(C) Not measured
Answer: (B) Low
Q#10: De-Normalization normally speeds up
(A) Data Retrieval
(B) Data Modification
(C) Development Cycle
(D) Data Replication
Answer: (A) Data Retrieval
Q#11: De-Normalization normally slows down
(A) Data Retrieval
(B) Data Modification
(C) Development Cycle
(D) Data Replication
Answer: (B) Data Modification
Q#12: Geography is a good example of
(A) One-dimensional Hierarchy
(B) Multidimensional Hierarchy
(C) Non-Dimensional
(D) Linear Hierarchy
Answer: (B) Multidimensional Hierarchy
Q#13: Partition elimination is not possible with
(A) Round-Robin
(B) De-normalization
(C) Normalization
Answer: (A) Round-Robin
Q#14: OLAP is analytical processing instead of transaction processing, and OLAP is a
(A) Physical database design
(B) Implementation technique
(C) Framework
Answer: (C) Framework
Q#15: ER is a logical design technique that seeks to remove the ____ in data.
(A) Redundancy
(B) Normalization
(C) Anomalies
Answer: (A) Redundancy
Q#16: ER is a ____ design technique that seeks to remove the redundancy in data.
(A) Logical
(B) Physical
(C) Data Dependent
(D) Transaction Dependent
Answer: (A) Logical
Q#17: Pre-computed ____ can solve performance problems.
(A) Aggregates
(B) Facts
(C) Dimensions
Answer: (A) Aggregates
Q#18: Extract, Transform, Load (ETL) process consists of steps which are
(A) Independent and interrelated
(B) Independent or interrelated
(C) Dependent and interrelated
(D) Dependent or interrelated
Answer: (A) Independent and interrelated
Q#19: In full extraction, data is extracted completely from the source system. Therefore there is no need to keep track of changes to the ____
(A) Data Source
(B) DWH
(C) Data Mart
Answer: (A) Data Source
Q#20: Data Extraction from source systems is a difficult task because source systems are
(A) Homogeneous
(B) Heterogeneous
(C) Identical
(D) Standardized
Answer: (B) Heterogeneous
Q#21: Lexical errors fall in which type of class of anomalies
(A) Syntactically Dirty Data
(B) Semantically Dirty Data
(C) Coverage Anomalies
(D) Missing Values Anomalies
Answer: (A) Syntactically Dirty Data
Q#22: The degree of similarity between two records, often measured by a numerical value between ____, usually depends on application characteristics.
(A) 0 and 1
(B) 0 and 10
(C) 0 and 100
(D) 0 and 99
Answer: (A) 0 and 1 – PG #169