Forum Discussion
Slow refresh time
Hi Justas4478 ,
A 10-minute refresh time for 30MB files with 1.18 million rows is not unusually long, but there are ways to speed it up. First, check the file format; CSV and Excel are slower than more efficient formats like Parquet. You can also optimize Power Query by removing unnecessary columns and steps early in the process. If you're merging large tables, try to minimize the data you're combining and avoid unnecessary transformations. Use Incremental Refresh if your dataset only changes partially (e.g., daily or monthly data), which can greatly reduce refresh time. Additionally, monitor your system’s resources (CPU and RAM) and close unnecessary applications during the refresh to ensure Power BI has enough memory to process the data quickly. Lastly, using the Performance Analyzer in Power BI can help pinpoint specific areas that are slowing down the refresh.
Hi Justas4478
If we are talking about flat files like CSV or Excel given the number of rows, 10 minutes isnt that long but there are factors that come into play other than the file size.
- the data, if excel, being in a single worksheet will refresh faster than the same number of rows but are distributed across multiple worksheets
- a file vs two or more with the same number of rows will refresh faster given the same transformations applied
- calculated columns and tables needed to be written in to memory so they add to the refresh time
- Power Query transformations applied
danextian Unfortunatelly one excel file canot hold all rows thats why I had to split it in to two files.