The process of combining two or more data sources into a single, unified view is known as _______.
- Data Aggregation
- Data Convergence
- Data Harmonization
- Data Integration
Explanation:
How does the snowflake schema differ from the star schema in terms of its structure?
- Snowflake schema has fact tables with fewer dimensions
- Snowflake schema is more complex and difficult to maintain
- Star schema contains normalized data
- Star schema has normalized dimension tables
The snowflake schema differs from the star schema in that it is more complex and can be challenging to maintain. In a snowflake schema, dimension tables are normalized, leading to a more intricate structure, while in a star schema, dimension tables are denormalized for simplicity and ease of querying.
A method used in data cleaning where data points that fall outside of the standard deviation or a set range are removed is called _______.
- Data Normalization
- Data Refinement
- Data Standardization
- Outlier Handling
Explanation:
In the context of data warehousing, what does the ETL process stand for?
- Efficient Transfer Logic
- Enhanced Table Lookup
- Extract, Transfer, Load
- Extract, Transform, Load
In data warehousing, ETL stands for "Extract, Transform, Load." This process involves extracting data from source systems, transforming it into a suitable format, and loading it into the data warehouse. Transformation includes data cleansing, validation, and structuring for analytical purposes.
In predictive analytics, what method involves creating a model to forecast future values based on historical data?
- Descriptive Analytics
- Diagnostic Analytics
- Prescriptive Analytics
- Time Series Forecasting
Time series forecasting is a predictive analytics method that focuses on modeling and forecasting future values based on historical time-ordered data. It is commonly used in various fields, including finance, economics, and demand forecasting.
Which OLAP operation involves viewing the data cube by selecting two dimensions and excluding the others?
- Dicing
- Drilling
- Pivoting
- Slicing
In OLAP (Online Analytical Processing), the operation of viewing the data cube by selecting two dimensions while excluding others is known as "Dicing." Dicing allows you to focus on specific aspects of the data cube to gain insights into the intersection of chosen dimensions.
Which of the following is NOT typically a function of ETL tools?
- Data Analysis
- Data Extraction
- Data Loading
- Data Transformation
ETL tools are primarily responsible for data Extraction, Transformation, and Loading (ETL). Data Analysis is typically not a function of ETL tools. Data analysis is performed using BI (Business Intelligence) tools or other analytics platforms after the data has been loaded into the data warehouse.
Which schema design is characterized by a central fact table surrounded by dimension tables?
- Hierarchical Schema
- Relational Schema
- Snowflake Schema
- Star Schema
A Star Schema is characterized by a central fact table that contains numerical performance measures (facts) and is surrounded by dimension tables that describe the dimensions associated with the facts. This design is commonly used in data warehousing to simplify query performance and reporting.
Why might an organization consider using a Data Warehouse Appliance?
- To accelerate data analytics and reporting
- To replace traditional file servers
- To save electricity costs
- To store unstructured data
An organization might consider using a Data Warehouse Appliance to accelerate data analytics and reporting. These appliances are purpose-built for data warehousing, offering high-speed data processing and storage capabilities, making them ideal for organizations seeking to improve the speed and efficiency of their data analysis and reporting processes.
In a data warehouse, a _______ is a large, subject-oriented, integrated, time-variant, and non-volatile collection of data that supports decision-making.
- Data Cube
- Data Lake
- Data Mart
- Data Warehouse
In a data warehouse, a Data Warehouse is a large, subject-oriented, integrated, time-variant, and non-volatile collection of data that supports decision-making. It is designed to provide a centralized repository of historical data for reporting and analysis.