Power BI Cheat sheet
A quick, practical guide to the Power BI basics to use in real projects and interviews.
1. Power BI Ecosystem
Power BI includes several components, each serving a specific purpose:
Power BI Desktop – report creation, data modeling, and DAX
Power BI Service – publishing, sharing, and scheduled refreshes
Power BI Mobile – dashboard access on phones and tablets
Gateway – secure connection between on‑premise data and the cloud
Report Builder – paginated, print‑friendly reporting
Dataflows – reusable cloud‑based data preparation
Most development work happens in Desktop while sharing and collaboration occur in the Service.
2. Import vs Direct Query
Import Mode
Data stored inside the Power BI model
Fast performance
Full DAX support
Direct Query
Queries run directly against the source
Suitable for real‑time scenarios
Slower and more restricted
Import Mode is typically preferred for performance‑heavy dashboards.
3. DAX Essentials
DAX powers calculations in Power BI. Common functions include:
SUM
AVERAGE
CALCULATE
FILTER
SUMX
DATESYTD and other time‑intelligence functions
Calculated Columns handle row‑level logic. Measures handle dynamic calculations that respond to filters. Measures are generally more efficient and widely used.
4. Data Modeling Basics
A strong data model is the foundation of a smooth Power BI experience.
The recommended structure is a Star Schema, consisting of:
Fact tables: numeric metrics such as Sales, Profit, Quantity
Dimension tables: descriptive attributes such as Date, Product, Customer
Benefits of a star schema include faster performance, simpler relationships, and cleaner DAX.
5. Power Query Essentials
Power Query handles data cleaning and shaping before it enters the model.
Common transformations include:
Removing duplicates
Splitting columns
Merging or appending tables
Changing data types
Unpivoting columns
Clear step names help maintain an understandable transformation flow.
6. Visualization Best Practices
Effective dashboards focus on clarity and simplicity.
Recommended practices:
Minimal, clean visuals
Consistent color usage
Tooltips for additional context
Limited slicers
Bookmarks for guided navigation
Avoid cluttered pages, overloaded pie charts, and heavy custom visuals that slow performance.
7. Performance Optimization Tips
A few adjustments can significantly improve report speed:
Reduce high‑cardinality fields
Prefer measures over calculated columns
Limit the number of visuals per page
Disable Auto Date/Time
Use Incremental Refresh for large datasets
Fast dashboards create a smoother user experience.
8. Row‑Level Security (RLS)
RLS restricts data visibility based on defined roles.
Typical scenarios include region‑based access, department‑based access, and hierarchical access for leadership. Roles are created in Desktop and assigned in the Service.
9. Useful Shortcuts
Copy/paste visuals: Ctrl + C / V
Duplicate page: Ctrl + D
Save: Ctrl + S
Format painter: Ctrl + Shift + C / V
Refresh: F5
These shortcuts speed up report development.
10. Difference Between a Report and a Dashboard
A report is a multi‑page, interactive document created in Power BI Desktop. A dashboard is a single‑page canvas created in the Power BI Service by pinning visuals from one or more reports.
Reports offer deeper exploration. Dashboards offer high‑level monitoring.
11. What a Date Table Should Include
A proper Date table typically contains:
continuous date column
year, quarter, month, week fields
fiscal attributes (if needed)
marked as the official Date Table in the model
A well‑structured Date table improves time‑intelligence calculations and model performance.
12. Common Data Types in Power BI
Power BI supports several data types:
Whole Number
Decimal Number
Date/Time
Text
Boolean
Currency
Correct data types ensure accurate calculations and sorting.
13. Common Relationship Cardinalities
Power BI relationships typically fall into:
One‑to‑Many (most common)
Many‑to‑One
Many‑to‑Many (used cautiously)
Single‑direction filtering is preferred unless cross‑filtering is required.
14. What Bookmarks Are Used For
Bookmarks capture the current state of a report page, including:
filters
visuals
visibility
navigation
They are often used for guided storytelling, custom navigation, and interactive buttons.
15. What Tooltips Can Add
Tooltips provide extra context without cluttering the main view. They can display:
additional metrics
trends
comparisons
mini‑visuals
Well-designed tooltips improve clarity without adding more visuals to the page.
16. What Drill‑Through Pages Do
Drill‑through pages allow deeper analysis of a specific entity such as:
customer
product
region
employee
Selecting a data point on a main page can open a detailed page focused on that selection.
17. What Q&A Visual Does
The Q&A visual allows natural‑language queries inside a report. It interprets typed questions and generates visuals automatically.
This feature is useful for exploratory analysis and quick insights.
18. What Decomposition Tree Is Used For
The decomposition tree breaks down a metric step‑by‑step to show:
contributors
categories
hierarchies
It is especially useful for root‑cause analysis and performance breakdowns.
19. What KPI Visual Represents
A KPI visual highlights progress toward a target using:
actual value
target value
trend indicator
It is commonly used in executive dashboards for quick performance checks.
20. Purpose of Hierarchies in Power BI
Hierarchies allow structured drill‑down paths such as
Year → Quarter → Month → Day or Country → State → City.
They make navigation smoother and help organize data exploration.
21. Purpose of Synonyms in the Q&A Feature
Synonyms help the Q&A visual understand different ways of referring to the same field. For example, “revenue,” “sales,” and “income” can all point to the same column.
This improves natural‑language querying.
22. What Conditional Formatting Can Highlight
Conditional formatting can emphasize:
high or low values
performance thresholds
trends
exceptions
It adds context without adding extra visuals.
23. Purpose of the Selection Pane
The Selection Pane manages visual visibility on a page. It is often used for:
custom navigation
layered visuals
bookmark‑based storytelling
It keeps complex layouts organized.
24. What Field Parameters Enable
Field parameters allow switching between different fields or measures inside a visual. This creates flexible, dynamic reports without multiple pages or visuals.
25. Purpose of the Performance Analyzer
The Performance Analyzer identifies slow visuals and long query times. It helps pinpoint bottlenecks in:
DAX
visuals
model structure
This tool is essential for tuning large reports.
26. What Aggregations Are Used For
Aggregations summarize large fact tables into smaller, pre‑calculated tables. They improve performance when working with massive datasets.
Power BI automatically chooses the right table based on the query.
27. Purpose of Incremental Refresh
Incremental Refresh updates only recent data instead of reloading the entire dataset. This reduces refresh time and improves reliability for large models.
28. What Composite Models Allow
Composite models combine Import and Direct Query in the same dataset. This offers flexibility when some data needs to be real‑time while other data can be cached.
29. Purpose of the Analyze Feature
The Analyze feature explains changes in a visual by identifying key drivers. It uses statistical analysis to highlight factors influencing increases or decreases.
This is helpful for quick insights without manual exploration.
30. Purpose of Drill‑Down and Drill‑Up
Drill‑down and drill‑up actions allow movement through different levels of a hierarchy. For example, a visual can move from Year → Quarter → Month → Day or from Country → State → City. This creates a natural way to explore data without switching pages.
Conclusion
Power BI becomes far more intuitive once the fundamentals are clear—data modeling, DAX, Power Query, and clean visualization design. This cheat sheet highlights the core concepts that consistently appear in real‑world analytics work and interview discussions.
