20+ BI Developer Interview Questions and Answers

Answering questions related to BI Developer interview

• I am using Power BI Pro

• I apply role level security by creating roles and assigning users to those roles

• I publish my visual by selecting the publish option in Power BI Desktop

• Challenges faced while building a dashboard include data quality issues, complex data relationships, and designing an intuitive user interface

Perspectives in analysis cubes are different views of the data that allow users to analyze data from different angles.

• Perspectives provide different combinations of dimensions and measures for analysis.

• They allow users to focus on specific aspects of the data.

• Perspectives can be used to create customized reports and dashboards.

• They help in simplifying complex data models by presenting a subset of data.

• For example, a sales perspective may include dimensions like product, regio...read more

Power BI is a business analytics service by Microsoft that provides interactive visualizations and business intelligence capabilities.

• Advantages: easy to use, integrates with other Microsoft products, allows for real-time data analysis, customizable dashboards

• Disadvantages: limited data capacity, requires a strong internet connection, can be expensive for larger organizations

• Power BI can be used for data modeling, data visualization, and report building

• Examples of Power BI fe...read more

Power BI is a business analytics service by Microsoft that provides interactive visualizations and business intelligence capabilities.

• Powerful data visualization tool

• Allows creation of interactive reports and dashboards

• Integrates with various data sources

• Offers natural language query and AI-powered insights

• Enables collaboration and sharing of reports

• Provides mobile access to reports and dashboards

I use simple language, visuals, and real-life examples to explain the dashboard to non-technical individuals.

• Use simple language and avoid technical jargon

• Include visuals like charts and graphs to make data easier to understand

• Provide real-life examples to illustrate the data and its implications

Self joins are used to join a table to itself. Types include inner, outer, and self-join.

• Self joins are used when a table needs to be joined with itself.

• Inner self join returns only the matching rows between the two instances of the table.

• Outer self join returns all rows from both instances of the table, with null values where there is no match.

• Self join can be used to find hierarchical relationships within a table.

• Example: Employee table with columns employee_id and manager_...read more

SQL Server has several system databases, each serving a unique purpose for database management and operations.

• master: Stores all system-level information, including logins and configuration settings.

• model: A template database used to create new databases with predefined settings.

• msdb: Manages scheduling and alerts for SQL Server Agent jobs, backups, and maintenance plans.

• tempdb: A temporary workspace for storing intermediate results and temporary tables.

Views are virtual tables that display data from one or more tables, while tables store data physically.

• Views are saved queries that act as virtual tables

• Views do not store data physically, but tables do

• Views can be used to simplify complex queries or restrict access to certain columns

• Tables are used to store data permanently

• Example: A view can be created to display only specific columns from a table

Filters in Power BI allow users to narrow down data based on specific criteria.

• Filters can be applied to visuals, pages, or the entire report.

• There are different types of filters such as visual-level, page-level, and report-level filters.

• Filters can be based on single or multiple values, ranges, or advanced conditions.

• Examples of filters include filtering data by date, category, or region.

• Filters can be applied manually or through interactions with other visuals.

Dynamic row level security is a feature that allows restrictions to be applied to rows of data based on user roles or attributes.

• Implemented in BI tools like Power BI or Tableau

• Security rules are defined based on user roles or attributes

• Users only see data that they are authorized to access

DAX stands for Data Analysis Expressions and is a formula language used in Power BI, Excel, and Analysis Services.

• DAX is used to create custom calculations, measures, and columns in Power BI and Excel.

• It allows for complex calculations and aggregations on data.

• DAX functions can be used to manipulate data and perform calculations like SUM, AVERAGE, and CALCULATE.

• DAX is optimized for querying large datasets and can improve performance compared to traditional Excel formulas.

Yes, I know triggers and indexes.

• Triggers are database objects that are automatically executed in response to certain events, such as insert, update, or delete operations.

• Indexes are database objects that improve the performance of queries by allowing them to quickly locate the data they need.

• Triggers can be used to enforce business rules, audit changes to data, or replicate data to other tables or databases.

• Indexes can be created on one or more columns of a table, and can be...read more

Power BI offers different license types for users.

• Power BI Free

• Power BI Pro

• Power BI Premium

• Power BI Embedded

Power Pivot, Query, and DAX are tools used in Microsoft Excel and Power BI for data modeling, querying, and analysis.

• Power Pivot is an Excel add-in used for data modeling and creating relationships between tables.

• Query is a tool used for extracting and transforming data from various sources.

• DAX (Data Analysis Expressions) is a formula language used for creating custom calculations and measures.

• These tools are commonly used in Power BI for creating data models and reports.

Reports can be created using various tools and techniques depending on the data source and requirements.

• Identify the data source and the type of report needed

• Choose a reporting tool such as Power BI, Tableau, or SSRS

• Design the report layout and add necessary visuals and filters

• Connect to the data source and import the data

• Create the report using the selected tool and publish it for users to access

Power Query is used for data transformation and loading, while DAX is a formula language for creating calculated columns and measures in Power BI.

• Power Query is used for data transformation and loading from various sources.

• DAX is a formula language used for creating calculated columns and measures in Power BI.

• Power Query is more focused on data preparation and shaping, while DAX is used for calculations and analysis.

• Power Query is a visual tool for ETL processes, while DAX is...read more

Power BI offers powerful data visualization capabilities but may have limitations in handling large datasets.

• Advantages: user-friendly interface, wide range of data connectors, interactive dashboards

• Disadvantages: limitations in handling large datasets, requires a good understanding of data modeling

• Example: Power BI allows users to easily create interactive reports and dashboards by connecting to various data sources such as Excel, SQL databases, and cloud services.

Sum is a function used to calculate the total of a set of values, while sum x is a specific value being summed.

• Sum calculates the total of a set of values, while sum x is a specific value being summed.

• Sum is used with a range of values, like sum(A1:A10), while sum x is used with a single value, like sum x = 10.

• Sum x is often used in mathematical equations to represent a specific value being summed.

Yes, stored procedures are pre-written SQL codes that can be saved and reused.

• Stored procedures are used to improve performance and security

• They can be called from within an application or directly from a database management system

• They can accept input parameters and return output parameters

• Examples include sp_help, sp_who, and sp_adduser

Query to display information about emp table

• SELECT * FROM emp;

• Use WHERE clause to filter results based on specific criteria

• Use ORDER BY clause to sort results in ascending or descending order

Row context filter is a filter applied to individual rows of data in a table or dataset.

• Row context filter is used to filter data at the row level in Power BI or other BI tools.

• It allows for filtering specific rows based on certain criteria or conditions.

• For example, you can apply a row context filter to only show sales data for a specific product category.

Writing queries on SQL Server is a fundamental skill for BI Developers.

• Understand the database schema and relationships

• Use appropriate SQL functions and operators

• Optimize queries for performance

• Test and validate results

• Document queries for future reference

Create an attendance report for tracking employee attendance

• Gather data on employee attendance including dates, times, and reasons for absence

• Organize the data into a clear and concise report format

• Include metrics such as total number of absences, average attendance rate, and trends over time

Views are virtual tables that display data from one or more tables in a database.

• Views are created using SELECT statements.

• They can be used to simplify complex queries.

• They can also be used to restrict access to sensitive data.

• Views do not store data themselves, but rather display data from underlying tables.

• They can be updated just like regular tables, but with some limitations.

Union combines and removes duplicates, Union All combines all rows including duplicates.

• Union removes duplicates, Union All includes duplicates

• Union is slower than Union All as it has to remove duplicates

• Union requires the same number of columns in both queries

• Union All does not require the same number of columns in both queries

Projects are specific tasks or assignments that require planning, execution, and completion within a defined timeframe.

• Projects involve a set of activities with a specific goal or outcome.

• They require resources such as time, budget, and manpower.

• Projects are typically temporary and have a defined start and end date.

• Examples: Developing a new BI dashboard, implementing a data warehouse, creating ETL processes.