How Excel files will be taken for Incremental Refresh

[likhithar]

Hello All,

I'm having sales file for every month,and I'm maintaining sales files in sales folder.In Power BI Desktop,I imported in folder format and combined sales files.As each is having each file in that folder(jan sales as jan-20 ,Feb sales as feb-20etc).

I'm refresh data in Power BI Desktop it will read all the data.In power BI service,if incremental refresh is enabled for that sales table,How it will know to read exactly the correct file(consider for jul-20 I imported the data and published to service).Now I placed Aug-20 File in the folder.How Power BI Service knows it has to read Aug-20 file only??

Period date will be maintaining for each file and modified date for Incremental Refresh (frequency is every month)

[lbendlin]

@likhithar Frankly with a monthly refresh cadence I would not bother setting up incremental refresh.

@likhithar 

Since you want to ingest Excel files your only option for incremental refresh would be the Last Modified Date of the file itself.  That will only work well if files from prior months will no longer be modified.  The moment you have data restatements in prior files you can pretty much forget about incremental refresh anyway, unless you choose a large enough window (for example "keep last five years and refresh last six months").

Power BI Incremental Refresh is designed to work with incoming data that is immutable. It is not well suited for data that keeps changing after the fact (ie the majority of real world business transaction data).