Chris Webb

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...

Performance testing Power BI Direct Lake models revisited: ensuring worst-case performance You now need to do a refresh of type clearValues followed by a full refresh to page all data out of memory for a Direct Lake model

Performance testing #PowerBI Direct Lake models revisited: ensuring worst-case performance blog.crossjoin.co.uk/2025/08/31/p...

Are you talking about Power Query? If so, it’s a mistake to think of each step being executed one after the other and therefore it’s usually not possible to find out how much time a single step takes.

Useful community tools and resources for #PowerBI and #MicrosoftFabric blog.crossjoin.co.uk/2025/08/24/u...

#PowerBI Copilot, AI Instructions and DAX query templates blog.crossjoin.co.uk/2025/08/17/p...

Power BI Copilot, AI Instructions and DAX measure definitions Adding measure definitions to Copilot AI Instructions helps users understand how measures work

#PowerBI Copilot, AI Instructions and DAX measure definitions blog.crossjoin.co.uk/2025/08/10/p...

Why Power BI Copilot seems to work better in Desktop than in the Service Changes to AI Instructions are not always applied immediately after publishing

Why do #PowerBI Copilot AI Instructions seem to work better in Desktop than in the Service? blog.crossjoin.co.uk/2025/08/03/w...

Power BI Copilot, AI Instructions and visualisation guidelines Control which visuals Copilot uses in responses

#PowerBI Copilot, AI Instructions and visualisation guidelines blog.crossjoin.co.uk/2025/07/27/p...

Power BI Copilot, AI Instructions and semantic model relationships Learn how Copilot works with measures and columns on different tables

#PowerBI Copilot, AI Instructions and semantic model relationships blog.crossjoin.co.uk/2025/07/20/p...