Chris Webb

Calculate, DAX fusion and filters on 0 in Power BI Filtering on 0 can be bad for performance if you're not careful

Calculate(), DAX fusion and filters on 0 in #PowerBI blog.crossjoin.co.uk/2026/01/25/c...

Measuring the time to display image visuals in Power BI with Performance Analyzer Large images can make reports slow

Measuring time to display for image visuals in #PowerBI with Performance Analyzer blog.crossjoin.co.uk/2026/01/18/m...

Measuring geocoding performance in Power BI map visuals using Performance Analyzer Geocoding could be making your report slow

Measuring geocoding performance in #PowerBI map visuals with Performance Analyzer blog.crossjoin.co.uk/2026/01/11/m...

Diagnosing Power BI DirectQuery performance problems caused by SQL queries that return large resultsets Large resultsets can be slow to read

Diagnosing #PowerBI DirectQuery performance problems caused by SQL queries that return large resultsets blog.crossjoin.co.uk/2026/01/04/d...

Diagnosing Power BI DirectQuery connection limit problems with Performance Analyzer See when a DirectQuery report is slow because there are limited connections back to the source

Diagnosing #PowerBI DirectQuery connection limit problems with Performance Analyzer blog.crossjoin.co.uk/2025/12/28/d...

Visualising Power BI Performance Analyzer data with a vibe-coded custom visual How Performance Analyzer data exports can be visualised in Power BI using a custom visual

Visualising #PowerBI Performance Analyzer data with a vibe-coded custom visual blog.crossjoin.co.uk/2025/12/21/v...

Power BI Copilot and report filters and slicers How report filters and slicers influence how Copilot answers questions

#PowerBI Copilot and report filters and slicers blog.crossjoin.co.uk/2025/12/14/p...

Stopping Power BI Copilot from answering questions from report visuals AI Instructions can force Copilot to get answers from the semantic model instead of the report

Stopping #PowerBI Copilot from answering questions from report visuals blog.crossjoin.co.uk/2025/12/07/s...

Impact of Calendar Based Time Intelligence on Power BI DirectQuery performance Significant performance improvements are possible but not in all cases

A look at the impact of calendar-based time intelligence on #PowerBI DirectQuery performance blog.crossjoin.co.uk/2025/11/30/a...

It might be a non-problem for you, but it’s a very real danger for lots of other people out there. But I’m not the PM in charge of apps so never say never…

Power BI, Build permissions and security Build permissions are not security!

#PowerBI Build permissions and security blog.crossjoin.co.uk/2025/11/23/p...

I suppose part of my job is to address the "Microsoft doesn't get us" problem - it's why I'm replying here! As for publish-to-web, I agree we probably wouldn't have built that (at least not in the same way) if we knew then what we know now. And because we know what we know now, we won't hide tabs.

So the next question will be - if you can already share thin reports which have this problem, why not allow hiding of tabs? To which I would answer: it would just lead to even more opportunities for misunderstanding how things work and accidental leaking of data, hence the reluctance.

Sharing thin reports is similar to hiding tabs - a lot of people assume that your users will only be able to see the data that is visible in the report, which is not the case (eg now people with Viewer access to a workspace can use the Explore feature)

No, I totally get how useful control over which tabs are visible would be. It's just that there are ways to see the data on those tabs even if they are hidden, so hiding a tab isn't secure. It's not about degrees of strictness, you're either secure or you aren't.

Oh, and security at the model level (granting/denying access to the model that is).

I've written a blog post on this that will be published on Sunday! Basically the semantic model is the security boundary, not the report. There are always ways to get around visibility settings; RLS and OLS are the only true security.

The trouble is that it couldn’t be made secure and while you might think that your users aren’t bothered about hacking pages they can’t see, if we did this there would immediately be complaints from customers who ignored the warnings and had users view data they should not have seen.

Linking queries run from DAX Studio to Workspace Monitoring and the Capacity Metrics app The RequestId value in DAX Studio's Server Timings is the same thing as the OperationId

Linking queries run from DAX Studio to Workspace Monitoring and the Capacity Metrics app blog.crossjoin.co.uk/2025/11/16/l...

Calling DAX UDFs from Power BI Copilot An example showing how Copilot can call a DAX UDF that does ABC analysis

Calling DAX UDFs from #PowerBI Copilot blog.crossjoin.co.uk/2025/11/09/c...

I think everyone is reading wayyyy too much into someone at Microsoft moving to a new job

Monitoring the DAX queries generated when the Power BI Copilot index is built The DAX queries get all the distinct values less than 100 characters long from text columns

Monitoring the DAX queries generated when the #PowerBI Copilot index is built blog.crossjoin.co.uk/2025/11/02/m...

Understanding the "Copilot analyzed only part of the model due to its size" warning in Power BI Copilot Learn how to control which columns Copilot indexes

Understanding the “Copilot analyzed only part of this model due to its size” warning in #PowerBI blog.crossjoin.co.uk/2025/10/26/u...

Monitor Fabric costs with Fabric Cost Analysis It's a solution built using Fabric for monitoring Fabric costs

Monitor Fabric costs with Fabric Cost Analysis blog.crossjoin.co.uk/2025/10/19/m...

First look at Fabric Graph: Analysing Power BI Import mode refresh job graphs Use Fabric's new graph database to analyse the jobs that make up a Power BI Import mode model refresh

First look at Fabric Graph: Analysing #PowerBI Import mode refresh job graphs blog.crossjoin.co.uk/2025/10/12/f...

Snowflake query tags in Power BI and Workspace Monitoring Link a Snowflake query to the Power BI operation that generated it

Snowflake query tags in #PowerBI and Workspace Monitoring blog.crossjoin.co.uk/2025/10/05/s...

Linking Fabric Warehouse SQL queries and Spark jobs to the Capacity Metrics App The OperationId can be used to find details of a TSQL query or Spark job

Linking Fabric Warehouse SQL queries and Spark jobs to the Capacity Metrics App blog.crossjoin.co.uk/2025/09/28/l...

Finding Power BI queries and refreshes that have been throttled with Workspace Monitoring The capacityThrottlingMs metric tells you if a query or refresh has been throttled

Finding #PowerBI queries and refreshes that have been throttled using Workspace Monitoring blog.crossjoin.co.uk/2025/09/21/f...

How to get the details of Power BI operations seen in the Capacity Metrics App The OperationId column can be used in Workspace Monitoring queries

How to get the details of #PowerBI operations seen in the Capacity Metrics App blog.crossjoin.co.uk/2025/09/14/h...

What happens when Power BI Direct Lake models hit guardrails? It depends on the type of Direct Lake model but you will either get warnings or errors and the model will fall back to DirectQuery if it can

What happens when #PowerBI Direct Lake models hit guardrails? blog.crossjoin.co.uk/2025/09/07/w...