Star schema in SQL. Fact updated Monthly dims updated daily

[DebbieE]

Hi all,

Just trying to get some refresh logic for power BI sorted and wondered if I could get some opinions.

Say you have a  few star schemas in SQL with conformed dimensions.

Star Schema 1. The Dims and Facts are updated daily

Star Schema 2. the Fact is updated monthly but uses the Dim that is updated daily. 

We always wanted to refresh Power BI At the same time as SQL so SQL and Power BI results always look the save (Avoiding confusion)

However For Star Schema 2, you have to refresh everything together. If you only refreshed at the same time as the fact table (Monthly), your Dims would be different to SQL, possibly causing a bit of confusion. 

If you refreshed at the daily rate, you will be refreshing fully every day, bringing in the latest dim information, the fact remains the same until it changes in SQL. 

Does anyone see any problems with the daily refresh? Or am I missing something and is there a better way of dealing with this logic? 

[parry2k]

@DebbieE sounds good. way to go. cheers!!

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[parry2k · Accepted solution]

@DebbieE it is not a different refresh schedule but incremental refresh will help since you will create a refresh policy in the incremental refresh, as there is no new data, there will be nothing to refresh. Read here for incremental refresh Incremental refresh for datasets and real-time data in Power BI - Power BI | Microsoft Docs

There are lot more blog posts on this so you should be able to put this together very easily.

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[DebbieE]

I will mention that to the guys creating the fact table so they can plan for a LastEditDate or update date. i dont honestly think a full refresh would hurt because its not a big model but this is definitely something we can plan in if neccessary. thanks

[parry2k]

@DebbieE why not set the incremental refresh on the fact table for star schema 2, since there is no new/change in data, now row will be refreshed, and dim will refresh daily.

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Learn about conditional formatting at Microsoft Reactor

My latest blog post The Power of Using Calculation Groups with Inactive Relationships (Part 1) (perytus.com) I would ❤ Kudos if my solution helped. 👉 If you can spend time posting the question, you can also make efforts to give Kudos to whoever helped to solve your problem. It is a token of appreciation!

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[DebbieE]

I wasnt aware that you could set different refreshes on different objects within the star schema. Could you explain how this works please or point me to some documentation?