Marco Russo
@marcorus.bsky.social
Consultant, speaker, book writer, mentor. Business Intelligence with Power BI, Analysis Services, and Power Pivot. Other info on sqlbi.com
𝗗𝗔𝗫 𝗟𝗶𝗯 is quickly becoming the shared home for UDFs in DAX: 𝘁𝗵𝗲 𝗰𝗼𝗺𝗺𝘂𝗻𝗶𝘁𝘆 𝗵𝗮𝘀 𝗮𝗹𝗿𝗲𝗮𝗱𝘆 𝗰𝗼𝗻𝘁𝗿𝗶𝗯𝘂𝘁𝗲𝗱 𝟯𝟬+ 𝗹𝗶𝗯𝗿𝗮𝗿𝗶𝗲𝘀 that you can import into your Power BI models using TMDL scripts.
Watch what DAX Lib is, why it matters, and how you can start using it.
Watch what DAX Lib is, why it matters, and how you can start using it.
Introducing DAX Lib
DAX Lib is an open-source repository of User-Defined Functions (UDFs) for Power BI, Fabric, and Analysis Services. Learn how simple it is to import a library...
youtu.be
December 12, 2025 at 10:04 AM
𝗗𝗔𝗫 𝗟𝗶𝗯 is quickly becoming the shared home for UDFs in DAX: 𝘁𝗵𝗲 𝗰𝗼𝗺𝗺𝘂𝗻𝗶𝘁𝘆 𝗵𝗮𝘀 𝗮𝗹𝗿𝗲𝗮𝗱𝘆 𝗰𝗼𝗻𝘁𝗿𝗶𝗯𝘂𝘁𝗲𝗱 𝟯𝟬+ 𝗹𝗶𝗯𝗿𝗮𝗿𝗶𝗲𝘀 that you can import into your Power BI models using TMDL scripts.
Watch what DAX Lib is, why it matters, and how you can start using it.
Watch what DAX Lib is, why it matters, and how you can start using it.
The 3rd edition of The Definitive Guide to DAX is available.
We have seen quality issues with the Kindle format. You might want to wait for that.
PDF is the best format for rendering, with no quality issues.
Enjoy DAX!
We have seen quality issues with the Kindle format. You might want to wait for that.
PDF is the best format for rendering, with no quality issues.
Enjoy DAX!
The Definitive Guide to DAX, Third Edition - SQLBI
The Definitive Guide to DAX is an authoritative resource for mastering the DAX language, which is pivotal for creating measures for semantic models in Micro
www.sqlbi.com
December 8, 2025 at 9:39 PM
The 3rd edition of The Definitive Guide to DAX is available.
We have seen quality issues with the Kindle format. You might want to wait for that.
PDF is the best format for rendering, with no quality issues.
Enjoy DAX!
We have seen quality issues with the Kindle format. You might want to wait for that.
PDF is the best format for rendering, with no quality issues.
Enjoy DAX!
Should you use RANK or stick with RANKX?
In which scenarios is one better than the other?
Make an informed choice with this article + video!
#powerbi #dax
https://www.sqlbi.com/articles/using-rank-instead-of-rankx-in-dax/
In which scenarios is one better than the other?
Make an informed choice with this article + video!
#powerbi #dax
https://www.sqlbi.com/articles/using-rank-instead-of-rankx-in-dax/
December 2, 2025 at 11:04 AM
Should you use RANK or stick with RANKX?
In which scenarios is one better than the other?
Make an informed choice with this article + video!
#powerbi #dax
https://www.sqlbi.com/articles/using-rank-instead-of-rankx-in-dax/
In which scenarios is one better than the other?
Make an informed choice with this article + video!
#powerbi #dax
https://www.sqlbi.com/articles/using-rank-instead-of-rankx-in-dax/
If you are at PASS Summit 2025, look for me at the Tabular Editor booth in the Exhibit Hall.
I will show a sneak preview of DAX Optimizer basic edition: no emails, no data access, no external tools required.
The easiest way to verify if your semantic model can be optimized.
Coming soon...
I will show a sneak preview of DAX Optimizer basic edition: no emails, no data access, no external tools required.
The easiest way to verify if your semantic model can be optimized.
Coming soon...
November 19, 2025 at 5:22 PM
If you are at PASS Summit 2025, look for me at the Tabular Editor booth in the Exhibit Hall.
I will show a sneak preview of DAX Optimizer basic edition: no emails, no data access, no external tools required.
The easiest way to verify if your semantic model can be optimized.
Coming soon...
I will show a sneak preview of DAX Optimizer basic edition: no emails, no data access, no external tools required.
The easiest way to verify if your semantic model can be optimized.
Coming soon...
Learn the differences between model-dependent and model-independent DAX user-defined functions in this article+video.
Bonus: tips to publish libraries of functions on daxlib.org.
#dax #powerbi
https://www.sqlbi.com/articles/model-dependent-and-model-independent-user-defined-functions-in-dax/
Bonus: tips to publish libraries of functions on daxlib.org.
#dax #powerbi
https://www.sqlbi.com/articles/model-dependent-and-model-independent-user-defined-functions-in-dax/
November 18, 2025 at 11:03 AM
Learn the differences between model-dependent and model-independent DAX user-defined functions in this article+video.
Bonus: tips to publish libraries of functions on daxlib.org.
#dax #powerbi
https://www.sqlbi.com/articles/model-dependent-and-model-independent-user-defined-functions-in-dax/
Bonus: tips to publish libraries of functions on daxlib.org.
#dax #powerbi
https://www.sqlbi.com/articles/model-dependent-and-model-independent-user-defined-functions-in-dax/
Top 10 products are a classic. Reporting which products are in the top 10 for several years is more challenging.
We are looking for 𝗲𝘃𝗲𝗿𝗴𝗿𝗲𝗲𝗻 𝗽𝗿𝗼𝗱𝘂𝗰𝘁𝘀: how to find them in DAX in this article+video.
#powerbi #dax
https://www.sqlbi.com/articles/find-the-products-in-the-top-10-every-year-with-dax/
We are looking for 𝗲𝘃𝗲𝗿𝗴𝗿𝗲𝗲𝗻 𝗽𝗿𝗼𝗱𝘂𝗰𝘁𝘀: how to find them in DAX in this article+video.
#powerbi #dax
https://www.sqlbi.com/articles/find-the-products-in-the-top-10-every-year-with-dax/
November 4, 2025 at 11:04 AM
Top 10 products are a classic. Reporting which products are in the top 10 for several years is more challenging.
We are looking for 𝗲𝘃𝗲𝗿𝗴𝗿𝗲𝗲𝗻 𝗽𝗿𝗼𝗱𝘂𝗰𝘁𝘀: how to find them in DAX in this article+video.
#powerbi #dax
https://www.sqlbi.com/articles/find-the-products-in-the-top-10-every-year-with-dax/
We are looking for 𝗲𝘃𝗲𝗿𝗴𝗿𝗲𝗲𝗻 𝗽𝗿𝗼𝗱𝘂𝗰𝘁𝘀: how to find them in DAX in this article+video.
#powerbi #dax
https://www.sqlbi.com/articles/find-the-products-in-the-top-10-every-year-with-dax/
I start to believe that one of the biggest misconceptions in data analytics is that dimensional modeling is for the data warehouse, whereas it is really for the data mart.
Someone should fix that.
Someone should fix that.
October 25, 2025 at 9:18 AM
I start to believe that one of the biggest misconceptions in data analytics is that dimensional modeling is for the data warehouse, whereas it is really for the data mart.
Someone should fix that.
Someone should fix that.
Today you have one task: update DAX Studio to 3.4.0.
If you have a model with DAX UDFs (user-defined functions) or Calendars, here is the version that correctly handles autocompletion and VPAX export.
𝗘𝘅𝗽𝗼𝗿𝘁 𝘁𝗼 𝗣𝗮𝗿𝗾𝘂𝗲𝘁? Now you can!
https://daxstudio.org/blog/v3_4_0-release/
If you have a model with DAX UDFs (user-defined functions) or Calendars, here is the version that correctly handles autocompletion and VPAX export.
𝗘𝘅𝗽𝗼𝗿𝘁 𝘁𝗼 𝗣𝗮𝗿𝗾𝘂𝗲𝘁? Now you can!
https://daxstudio.org/blog/v3_4_0-release/
October 24, 2025 at 6:46 AM
Today you have one task: update DAX Studio to 3.4.0.
If you have a model with DAX UDFs (user-defined functions) or Calendars, here is the version that correctly handles autocompletion and VPAX export.
𝗘𝘅𝗽𝗼𝗿𝘁 𝘁𝗼 𝗣𝗮𝗿𝗾𝘂𝗲𝘁? Now you can!
https://daxstudio.org/blog/v3_4_0-release/
If you have a model with DAX UDFs (user-defined functions) or Calendars, here is the version that correctly handles autocompletion and VPAX export.
𝗘𝘅𝗽𝗼𝗿𝘁 𝘁𝗼 𝗣𝗮𝗿𝗾𝘂𝗲𝘁? Now you can!
https://daxstudio.org/blog/v3_4_0-release/
This article+video describes when to use VALUES in the table grouped by SUMMARIZE, also mentioning why SUMMARIZECOLUMNS does not have that option.
#powerbi #dax
https://www.sqlbi.com/articles/using-values-in-summarize/
#powerbi #dax
https://www.sqlbi.com/articles/using-values-in-summarize/
October 21, 2025 at 10:04 AM
This article+video describes when to use VALUES in the table grouped by SUMMARIZE, also mentioning why SUMMARIZECOLUMNS does not have that option.
#powerbi #dax
https://www.sqlbi.com/articles/using-values-in-summarize/
#powerbi #dax
https://www.sqlbi.com/articles/using-values-in-summarize/
Yesterday at dataMinds.be I asked the audience how many experienced disk defrag.
I was talking about Delta/Parquet files in DirectLake.
>50% raised their hands.
Next time, I'll ask about index rebuild on SQL Server.
We are so back.
I was talking about Delta/Parquet files in DirectLake.
>50% raised their hands.
Next time, I'll ask about index rebuild on SQL Server.
We are so back.
October 8, 2025 at 10:16 AM
Yesterday at dataMinds.be I asked the audience how many experienced disk defrag.
I was talking about Delta/Parquet files in DirectLake.
>50% raised their hands.
Next time, I'll ask about index rebuild on SQL Server.
We are so back.
I was talking about Delta/Parquet files in DirectLake.
>50% raised their hands.
Next time, I'll ask about index rebuild on SQL Server.
We are so back.
Spoiler: 800+ pages.
Not ready to announce the official release date yet, but the third edition of The Definitive Guide to DAX has broken the 800-page barrier.
But hey, there are many figures!
Coming soon...
Not ready to announce the official release date yet, but the third edition of The Definitive Guide to DAX has broken the 800-page barrier.
But hey, there are many figures!
Coming soon...
October 4, 2025 at 10:02 AM
Spoiler: 800+ pages.
Not ready to announce the official release date yet, but the third edition of The Definitive Guide to DAX has broken the 800-page barrier.
But hey, there are many figures!
Coming soon...
Not ready to announce the official release date yet, but the third edition of The Definitive Guide to DAX has broken the 800-page barrier.
But hey, there are many figures!
Coming soon...
I will be speaking live about UDF on Analytics Endeavors' channel on October 8 (morning in the US, late afternoon in Europe).
Set a reminder!
#dax #usd #live #powerbi
Set a reminder!
#dax #usd #live #powerbi
User-defined functions [UDFs] in DAX (With Marco Russo)
DESCRIPTION 📄In September 2025, Microsoft introduced a new feature in Power BI and in the DAX language: the ability to create user-defined functions (UDFs)....
www.youtube.com
September 30, 2025 at 4:28 PM
Simon Sabin and I sit down and chat to answer one simple question: why bother with conferences in 2026?
In the chat, we talk about meeting peers, asking real questions, and learning from battle-tested content (not vendor demos).
Watch (or just listen to) the video:
https://youtu.be/zwGDfL-B3jQ
In the chat, we talk about meeting peers, asking real questions, and learning from battle-tested content (not vendor demos).
Watch (or just listen to) the video:
https://youtu.be/zwGDfL-B3jQ
September 27, 2025 at 7:34 AM
Simon Sabin and I sit down and chat to answer one simple question: why bother with conferences in 2026?
In the chat, we talk about meeting peers, asking real questions, and learning from battle-tested content (not vendor demos).
Watch (or just listen to) the video:
https://youtu.be/zwGDfL-B3jQ
In the chat, we talk about meeting peers, asking real questions, and learning from battle-tested content (not vendor demos).
Watch (or just listen to) the video:
https://youtu.be/zwGDfL-B3jQ
I will be delivering a "Mastering DAX" Workshop in Lugano, Switzerland, from October 28-30, 2025.
This workshop is also near Northern Italy, France, and Southern Germany.
The workshop is in English.
For more details, visit: https://www.sqlbi.com/p/mastering-dax-workshop-lugano-oct-28-30-2025/
This workshop is also near Northern Italy, France, and Southern Germany.
The workshop is in English.
For more details, visit: https://www.sqlbi.com/p/mastering-dax-workshop-lugano-oct-28-30-2025/
September 25, 2025 at 8:31 AM
I will be delivering a "Mastering DAX" Workshop in Lugano, Switzerland, from October 28-30, 2025.
This workshop is also near Northern Italy, France, and Southern Germany.
The workshop is in English.
For more details, visit: https://www.sqlbi.com/p/mastering-dax-workshop-lugano-oct-28-30-2025/
This workshop is also near Northern Italy, France, and Southern Germany.
The workshop is in English.
For more details, visit: https://www.sqlbi.com/p/mastering-dax-workshop-lugano-oct-28-30-2025/
Watch a 30-minute chat with Jay recorded at FabCon25 Europe this week.
@jaypowerbi.sky.social is the product manager of DAX.
We talk about the new features just released: User-defined functions (UDFs) and Calendar-based time intelligence.
#dax #fabconeurope25
@jaypowerbi.sky.social is the product manager of DAX.
We talk about the new features just released: User-defined functions (UDFs) and Calendar-based time intelligence.
#dax #fabconeurope25
DAX UDFs and Calendar-based time intelligence: A chat with Jay
Here is a chat with Jeroen (Jay) ter Heerdt, the product manager for DAX, talking about the new features released today: User-defined functions (UDFs) and Ca...
youtu.be
September 20, 2025 at 8:16 AM
Watch a 30-minute chat with Jay recorded at FabCon25 Europe this week.
@jaypowerbi.sky.social is the product manager of DAX.
We talk about the new features just released: User-defined functions (UDFs) and Calendar-based time intelligence.
#dax #fabconeurope25
@jaypowerbi.sky.social is the product manager of DAX.
We talk about the new features just released: User-defined functions (UDFs) and Calendar-based time intelligence.
#dax #fabconeurope25
We finally have 𝘂𝘀𝗲𝗿-𝗱𝗲𝗳𝗶𝗻𝗲𝗱 𝗳𝘂𝗻𝗰𝘁𝗶𝗼𝗻𝘀 (𝗨𝗗𝗙) in DAX!
Don't make mistakes; this is not a user data function in Fabric.
This is a new DAX feature, the most important one in the last five years.
Read/watch more:
https://www.sqlbi.com/articles/introducing-user-defined-functions-in-dax/
Don't make mistakes; this is not a user data function in Fabric.
This is a new DAX feature, the most important one in the last five years.
Read/watch more:
https://www.sqlbi.com/articles/introducing-user-defined-functions-in-dax/
September 16, 2025 at 9:11 AM
We finally have 𝘂𝘀𝗲𝗿-𝗱𝗲𝗳𝗶𝗻𝗲𝗱 𝗳𝘂𝗻𝗰𝘁𝗶𝗼𝗻𝘀 (𝗨𝗗𝗙) in DAX!
Don't make mistakes; this is not a user data function in Fabric.
This is a new DAX feature, the most important one in the last five years.
Read/watch more:
https://www.sqlbi.com/articles/introducing-user-defined-functions-in-dax/
Don't make mistakes; this is not a user data function in Fabric.
This is a new DAX feature, the most important one in the last five years.
Read/watch more:
https://www.sqlbi.com/articles/introducing-user-defined-functions-in-dax/
Read our first article and watch the video about the new calendar-based time intelligence feature in DAX and Power BI.
Helpful for Gregorian, necessary for non-Gregorian calendars.
#powerbi #dax #timeintelligence
https://www.sqlbi.com/articles/introducing-calendar-based-time-intelligence-in-dax/
Helpful for Gregorian, necessary for non-Gregorian calendars.
#powerbi #dax #timeintelligence
https://www.sqlbi.com/articles/introducing-calendar-based-time-intelligence-in-dax/
September 16, 2025 at 8:26 AM
Read our first article and watch the video about the new calendar-based time intelligence feature in DAX and Power BI.
Helpful for Gregorian, necessary for non-Gregorian calendars.
#powerbi #dax #timeintelligence
https://www.sqlbi.com/articles/introducing-calendar-based-time-intelligence-in-dax/
Helpful for Gregorian, necessary for non-Gregorian calendars.
#powerbi #dax #timeintelligence
https://www.sqlbi.com/articles/introducing-calendar-based-time-intelligence-in-dax/
There were so many things to announce at #fabconeurope that 𝗠𝗶𝗰𝗿𝗼𝘀𝗼𝗳𝘁 𝗳𝗼𝗿𝗴𝗼𝘁 to include the biggest innovations in DAX and semantic models in the last 6 years:
- 𝗨𝘀𝗲𝗿-𝗱𝗲𝗳𝗶𝗻𝗲𝗱 𝗳𝘂𝗻𝗰𝘁𝗶𝗼𝗻𝘀 (in DAX)
- 𝗖𝗮𝗹𝗲𝗻𝗱𝗮𝗿-𝗯𝗮𝘀𝗲𝗱 time intelligence
Watch out for articles on www.sqlbi.com coming in the next hour!
- 𝗨𝘀𝗲𝗿-𝗱𝗲𝗳𝗶𝗻𝗲𝗱 𝗳𝘂𝗻𝗰𝘁𝗶𝗼𝗻𝘀 (in DAX)
- 𝗖𝗮𝗹𝗲𝗻𝗱𝗮𝗿-𝗯𝗮𝘀𝗲𝗱 time intelligence
Watch out for articles on www.sqlbi.com coming in the next hour!
September 16, 2025 at 8:22 AM
There were so many things to announce at #fabconeurope that 𝗠𝗶𝗰𝗿𝗼𝘀𝗼𝗳𝘁 𝗳𝗼𝗿𝗴𝗼𝘁 to include the biggest innovations in DAX and semantic models in the last 6 years:
- 𝗨𝘀𝗲𝗿-𝗱𝗲𝗳𝗶𝗻𝗲𝗱 𝗳𝘂𝗻𝗰𝘁𝗶𝗼𝗻𝘀 (in DAX)
- 𝗖𝗮𝗹𝗲𝗻𝗱𝗮𝗿-𝗯𝗮𝘀𝗲𝗱 time intelligence
Watch out for articles on www.sqlbi.com coming in the next hour!
- 𝗨𝘀𝗲𝗿-𝗱𝗲𝗳𝗶𝗻𝗲𝗱 𝗳𝘂𝗻𝗰𝘁𝗶𝗼𝗻𝘀 (in DAX)
- 𝗖𝗮𝗹𝗲𝗻𝗱𝗮𝗿-𝗯𝗮𝘀𝗲𝗱 time intelligence
Watch out for articles on www.sqlbi.com coming in the next hour!
Introducing AI and Agentic Development for Power BI: an article that explores concepts and scenarios for integrating AI and AI agents into BI development, with specific examples for Power BI.
https://www.sqlbi.com/articles/introducing-ai-and-agentic-development-for-business-intelligence/
https://www.sqlbi.com/articles/introducing-ai-and-agentic-development-for-business-intelligence/
September 9, 2025 at 10:03 AM
Introducing AI and Agentic Development for Power BI: an article that explores concepts and scenarios for integrating AI and AI agents into BI development, with specific examples for Power BI.
https://www.sqlbi.com/articles/introducing-ai-and-agentic-development-for-business-intelligence/
https://www.sqlbi.com/articles/introducing-ai-and-agentic-development-for-business-intelligence/
If you're in Toronto, don't miss the Toronto Power Platform UG meeting on August 20, 6pm EDT.
Alberto Ferrari presents "Understanding visual calculations in Power BI"
Follow the link for more details and to register (free!):
Alberto Ferrari presents "Understanding visual calculations in Power BI"
Follow the link for more details and to register (free!):
Maestro Alberto Ferrari in Toronto!, Wed, Aug 20, 2025, 6:00 PM | Meetup
Hello everyone,
We are honored and pleased to have the Fabric, Power BI and DAX international guru and the bestselling books author Alberto Ferrari. He generously accepted
www.meetup.com
August 15, 2025 at 2:03 PM
If you're in Toronto, don't miss the Toronto Power Platform UG meeting on August 20, 6pm EDT.
Alberto Ferrari presents "Understanding visual calculations in Power BI"
Follow the link for more details and to register (free!):
Alberto Ferrari presents "Understanding visual calculations in Power BI"
Follow the link for more details and to register (free!):