Forum Discussion
Power Query taking forever to load or refresh
Hi, Anonymous
It will depend on the number of times a source file (query) is duplicated or referenced and also the number of query transformations. The same file can be loaded multiple times.
Usually PQ would load the source data twice: First while retrieving the metadata to generate the evaluation plan and then to fetch the data itself.
You might considering using the M function Table.Buffer Table.Buffer - PowerQuery M | Microsoft Docs This can reduce the number of re-reading the base file.
You can find more performance tips on this blog here: Speed/Performance aspects – The BIccountant
Refer:
Why does Power BI "Load" much more data (volume) than what's in my source file?
XLSX file 10MB, but Power Query loads 100MB into Power Query
Best Regards,
Community Support Team _ Zeon Zheng
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.
Problem,
Power Query In Excel refresh taking excessive long time to refresh (> 10 Minutes Power PC and > 30 Minutes thin client)
Systematic Investigation
In Queries & Connections refreshed each table. Of 29 Tables ( none more than 3,000 lines) found one table taking long time to refresh. All of my tables have filters. This particular table had Grouped columns. I used Grouping to quickly hide and unhide columns when hunting for data in tables.
Solution
Removed Grouped Colums and problem solved. Not sure if filters affect refresh time (Not that I have noticed)
Lesson
No Grouping in Tables