Store and "freeze" column data prior refresh

[pratafran]

Hello!

I have a tracking report with a list of shipments and their ETA-D (Estimated Time of Arrival to Destination).

My PBI refreshes every 30 min to reflect tracking information in a report and show the most recent ETA (pulled from online data source)

I want to create a measure to compare current ETA versus previous ETA and monitor if there are big changes (for example, a +1 week of delay vs previous ETA).

The problem is that when it automatically refreshes, I lost the previous data to make the comparisson.

Is there a way of storing data (like copy and pasting column values to another) upon refresh?, that way I would be able to keep two columns, the ETA that automatically refreshes and overwrite with the most recent date, and a secondary column "previous ETA" that is overwritted with the column ETA data prior each update.

Thanks

[v-yuta-msft · Accepted solution]

@pratafran ,

I'm afraid this could not be achieved beacause power bi will not save the data which is not existing in the data source. When you refresh the dataset, if you have deleted the old data in your data source, these part of data will also not appear in power bi dataset.

Community Support Team _ Jimmy Tao

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

[pratafran]

Thanks everybody for the answers. Unfortunately it seems there is not solution yet for this.

I made a workaround by putting an intermediate process outside BI (macro downloading a daily copy of the tracking database to excel file in a folder) and then importing the folder to PBI (one file per day) and compiling them all in an histoical database. I eliminate duplicates and only keep the records where there is ETA changes, that way I'm able to have the log.

Regards

[nicodem]

Hello,

Could you give me more info on the macro you made, please ? How did you do that ?

[Greg_Deckler]

This one has been asked quite a few times over the years. There are ways to do this but they are manual. May be some third party tool out there that can help. Probably some hacks and work-a-rounds but every 30 minutes, that's tough. For example, duplicate your query, load data, turn off refresh. But that will not work in your case I do not believe. Seems to me that you need to implement some sort of staging table where you can implement this logic and then point Power BI to that. Others may have better options.