CS614 Midterm Solved MCQs by Arslan

CS614- Data Warehousing · Solved MCQ(S) · From Midterm Papers (1 TO 22 Lectures) · Oct 26,2017 · BY Arslan · V-U

Updated.

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.