CS614 Midterm MCQs by Arslan

CS614- Data Warehousing · Solved MCQ(S) · From Midterm Papers (1 TO 22 Lectures) · BY Arslan Arshad · Nov 21,2016 · AKMP01

CS614 - Data Warehousing - Midterm Papers Solved MCQ(S) (1 TO 22 Lectures)

1. If there are N records in a table, then the selectivity of primary key column is

 1/N PG # 22

•  N/2
•  lg(N)

2. _________ is one class of decision support environment.

 OLAP PG # 30

•  OLTP
•  Data Cleansing
•  ETL

3. The users of data warehouse are ________

•  Decision makers
•  Knowledge workers

 Both Knowledge workers and Decision makers PG # 18

The users of data warehouse are knowledge workers in other words they are decision makers in the organization.

4. The users of data warehouse are knowledge workers in other words they are _________ in the organization.

 Decision maker PG # 18

•  Manager
•  Database Administrator
•  DWH Analyst

5. Effects of de-normalization on database performance are

 Unpredictable PG # 62

•  Predictable
•  Conventional
•  Unsurprising

6. OLAP is used for analytical process. For analytical processing we need

 Multi-level aggregates PG # 74

•  Record level access
•  Data level access
•  Row level access

7. Multidimensional databases typically use proprietary __________ format to store pre- summarized cube structures.

 File PG # 79

•  Application
•  Aggregate
•  Database

8. Normally Selectivity of query in OLTP system is

 High PG # 30

•  Low
•  Not measured

9. Normally Selectivity of query in data warehouse is

•  High

 Low PG # 30

•  Not measured

10. De-Normalization normally speeds up

 Data Retrieval PG # 51

•  Data Modification
•  Development Cycle
•  Data Replication

11. De-Normalization normally slows down

•  Data Retrieval

 Data Modification PG # 51

•  Development Cycle
•  Data Replication

De-normalization usually speeds up data retrieval, but it can slow the data modification processes.