Database

Database

Data Warehousing has 30 Questions

Data scrubbing is which of the following?

A process to reject data from the data warehouse and to create the necessary indexes
A process to load the data in the data warehouse and to create the necessary indexes
A process to upgrade the quality of data after it is moved into a data warehouse
A process to upgrade the quality of data before it is moved into a data warehouse
A data mart is designed to optimize the performance for well-defined and predicable uses.

True
False
The @active data warehouse architecture includes which of the following?

At least one data mart
Data that can extracted from numerous internal and external sources
Near real-time updates
All of the above.
Successful data warehousing requires that a formal program in total quality management (TQM) be implemented.

True
False
A goal of data mining includes which of the following?

To explain some observed event or condition
To confirm that data exists
To analyze data for expected relationships
To create a new data warehouse
Data in operational systems are typically fragmented and inconsistent.

True
False
An operational system is which of the following?

A system that is used to run the business in real time and is based on historical data.
A system that is used to run the business in real time and is based on current data.
A system that is used to support decision making and is based on current data.
A system that is used to support decision making and is based on historical data.
Most operational systems are based on the use of transient data.

True
False
A data warehouse is which of the following?

Can be updated by end users.
Contains numerous naming conventions and formats.
Organized around important subject areas.
Contains only current data.
Independent data marts are often created because an organization focuses on a series of short-term business objectives.

True
False
A snowflake schema is which of the following types of tables?

Fact
Dimension
Helper
All of the above
Joining is the process of partitioning data according to predefined criteria.

True
False
The generic two-level data warehouse architecture includes which of the following?

At least one data mart
Data that can extracted from numerous internal and external sources
Near real-time updates
All of the above.
The role of the ETL process is to identify erroneous data and to fix them.

True
False
Fact tables are which of the following?

Completely denoralized
Partially denoralized
Completely normalized
Partially normalized
Data in the data warehouse are loaded and refreshed from operational systems.

True
False
Data transformation includes which of the following?

A process to change data from a detailed level to a summary level
A process to change data from a summary level to a detailed level
Joining data from one source into various sources of data
Separating data from one source into various sources of data
Star schema is suited to online transaction processing, and therefore is generally used in operational systems, operational data stores, or an EDW.

True
False
Reconciled data is which of the following?

Data stored in the various operational systems throughout the organization.
Current data intended to be the single source for all decision support systems.
Data stored in one operational system in the organization.
Data that has been selected and formatted for end-user support applications.
Periodic data are data that are physically altered once added to the store.

True
False
The load and index is which of the following?

A process to reject data from the data warehouse and to create the necessary indexes
A process to load the data in the data warehouse and to create the necessary indexes
A process to upgrade the quality of data after it is moved into a data warehouse
A process to upgrade the quality of data before it is moved into a data warehouse
Both status data and event data can be stored in a database.

True
False
The extract process is which of the following?

Capturing all of the data contained in various operational systems
Capturing a subset of the data contained in various operational systems
Capturing all of the data contained in various decision support systems
Capturing a subset of the data contained in various decision support systems
Static extract is used for ongoing warehouse maintenance.

True
False
A star schema has what type of relationship between a dimension and fact table?

Many-to-many
One-to-one
One-to-many
All of the above.
Data scrubbing can help upgrade data quality; it is not a long-term solution to the data quality problem.

True
False
Transient data is which of the following?

Data in which changes to existing records cause the previous version of the records to be eliminated
Data in which changes to existing records do not cause the previous version of the records to be eliminated
Data that are never altered or deleted once they have been added
Data that are never deleted once they have been added
Every key used to join the fact table with a dimensional table should be a surrogate key.

True
False
A multifield transformation does which of the following?

Converts data from one field into multiple fields
Converts data from multiple fields into one field
Converts data from multiple fields into multiple fields
All of the above
Derived data are detailed, current data intended to be the single, authoritative source for all decision support applications.

True
False