The process of comparing current data with historical data to track performance over time is known as _______.
- Correlation
- Descriptive Analysis
- Regression
- Trend Analysis
The process of comparing current data with historical data to track performance over time is known as Trend Analysis. It helps identify patterns and make informed decisions based on historical trends. Correlation, Regression, and Descriptive Analysis have different objectives in data analysis.
What is the significance of 'star schema' in data warehousing and how does it benefit data analysis?
- It focuses on hierarchical organization of data.
- It only supports unstructured data.
- It simplifies the data model by using a single central table for facts, surrounded by dimension tables.
- It utilizes a complex network of interconnected tables for storing data.
The 'star schema' simplifies data warehousing by centralizing facts in a main table surrounded by dimension tables. This design enhances query performance and simplifies data analysis tasks by providing a clear structure for relationships between data points.
For a database containing millions of records, which strategy would you employ to speed up query response times?
- Data Partitioning
- Denormalization
- Full Table Scan
- Indexing
Indexing is a strategy to speed up query response times in a large database. By creating indexes on columns frequently used in queries, the database engine can quickly locate the required data without performing full table scans, leading to improved performance.
Which type of chart is best suited for displaying hierarchical data?
- Line chart
- Pie chart
- Scatter plot
- Tree map
A tree map is specifically designed for displaying hierarchical data, where each branch represents a category broken down into subcategories. Tree maps are effective in visualizing the hierarchical structure and relative proportions within the data.
______ Score' is a popular metric for gauging overall customer experience and satisfaction.
- Customer Satisfaction
- Experience
- Net Promoter
- Service
'Net Promoter Score' (NPS) is a widely used metric that measures customer satisfaction and loyalty. It is calculated based on the likelihood of customers recommending a company's product or service to others.
The concept of _______ is crucial in time series analysis, representing the correlation between points at different times.
- Autocorrelation
- Correlation Coefficient
- Covariance
- Cross-correlation
Autocorrelation measures the correlation of a time series with its own past values at different lags. It helps identify patterns and dependencies within the time series data.
What is the main benefit of using a cloud-based data warehouse over a traditional data warehouse?
- Cost
- Performance
- Scalability
- Security
The main benefit is scalability. Cloud-based data warehouses offer the ability to scale resources up or down based on demand, providing flexibility and cost-effectiveness compared to traditional warehouses with fixed hardware.
In advanced data warehousing, ________ is used for real-time data processing and analytics.
- Columnar Storage
- Data Sharding
- In-Memory Computing
- Stream Processing
In advanced data warehousing, Stream Processing is used for real-time data processing and analytics. This technique allows for the processing of data as it is generated, enabling quick insights and analysis in real-time scenarios.
The _________ sorting algorithm is efficient for datasets that are already substantially sorted because it has minimal time complexity in best-case scenarios.
- Bubble
- Insertion
- Merge
- Quick
The Insertion sorting algorithm is efficient for datasets that are already substantially sorted because it has minimal time complexity in best-case scenarios. Its adaptive nature makes it suitable for nearly sorted data.
For a project requiring the extraction of specific data points from multiple e-commerce sites, what scraping strategy would be most effective?
- Beautiful Soup
- Headless Browsing
- Regular Expressions
- XPath
Beautiful Soup is a Python library that is effective for web scraping, particularly when dealing with HTML and XML. XPath is used for navigating XML documents, Regular Expressions for pattern matching, and Headless Browsing for automated interaction with websites.