BI Data Warehouse Developer Interview Questions and Answers

Time travel implementation involves storing historical data in a data warehouse for analysis and reporting.

• Implement slowly changing dimensions to track changes over time

• Use effective date ranges to capture when data was valid

• Consider using snapshot tables to store historical data at specific points in time

DAX is a formula language used in Power BI for data analysis and optimization.

• DAX stands for Data Analysis Expressions

• Used to create calculated columns, measures, and calculated tables

• Optimization techniques include avoiding nested functions and using variables

• Examples: SUM, AVERAGE, CALCULATE functions

Query folding techniques are used to optimize query performance by pushing operations to the data source.

• Query folding allows Power Query to push operations to the data source instead of loading all data into memory.

• It helps reduce the amount of data transferred between the data source and Power Query, improving performance.

• Common query folding techniques include filter folding, join folding, and aggregation folding.

• For example, filtering data at the source before loading it ...read more

Power BI offers interactive visualizations, easy data integration, and seamless collaboration.

• Interactive visualizations make data analysis easier and more intuitive

• Easy data integration allows for combining data from multiple sources

• Seamless collaboration features enable sharing and discussing insights with team members

• Power BI offers a wide range of connectors for various data sources, such as Excel, SQL Server, Salesforce, etc.