Reuse an Existing Power BI Dataset to Build a New Report?

PL-300 By islever Editorial Last updated

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Short answer

A Connect the new report to the existing Power BI dataset so its data model and measures are reused without re-importing the Excel file.

Question

For the sales department at your company, you publish a Power BI report that imports data from a Microsoft Excel file located in a Microsoft SharePoint folder.
The data model contains several measures.
You need to create a Power BI report from the existing data. The solution must minimize development effort.
Which type of data source should you use?
  1. Power BI dataset Correct Answer
  2. a SharePoint folder
  3. Power BI dataflows
  4. an Excel workbook

Key Takeaways

The test is whether you recognise a published semantic model (dataset) as a reusable data source; the trap is assuming you must point at the underlying SharePoint/Excel file again because that is where the raw data lives.

When a published Power BI report already contains a data model with measures, a new report should be built on that existing Power BI dataset rather than re-importing the SharePoint Excel file. This page confirms why the dataset is the minimum-effort data source and explains why the SharePoint folder and Excel workbook options fail the requirement.

Common mistake: Choosing 'a SharePoint folder' (or 'an Excel workbook') because the raw data physically lives there — that answer forces you to redo the import, cleansing and measure authoring, which directly violates the 'minimize development effort' requirement.

Expert Analysis

Why the Answer Is Correct

Publishing a Power BI report from Power BI Desktop also publishes its semantic model as a Power BI dataset in the service, and that dataset carries the tables, relationships and all the DAX measures built for the sales model. Power BI Desktop and the Power BI service both allow a new report to be authored directly against that existing dataset via 'Get data' > 'Power BI datasets' (or 'New report' on the dataset in the service). Because the cleansing steps and measures already exist in the model, the second report inherits them with zero rework — precisely what 'minimize development effort' demands. Nomios states the logic plainly: the model already exists, so you should "connect to the existing dataset" instead of starting over from the SharePoint files.

Why the Other Options Are Wrong

A SharePoint folder (B) and an Excel workbook (D) are physical file locations — connecting to them creates a brand-new Power BI Desktop model, so every query, relationship and measure must be re-created or copy-pasted, which is the opposite of minimum effort. Power BI dataflows (C) would require you to define and maintain a new dataflow and then still build a fresh model on top of it, adding work rather than reusing the existing measures. The objection raised by Uhoh that a dataset is "NOT a data source" does not hold for this scenario: the exam treats the published semantic model as a connectable data source for authoring new reports, and the whole point of the question is that the model (not the file) is what should be reused.

Community Comment Notes

Nomios's highly upvoted explanation frames the decision around the already-published report and its measures, and rashjan summarises it as "reuse the existing dataset". Hoeishetmogelijk notes the wording only makes sense once you realise there are two reports and the second can reuse the first one's dataset, while ZSun reads it the same way: publish the first report, then build the second from its dataset. The dissenting camp (TopCat1583, Green13) argues the data source must be the SharePoint folder, but NatRob's observation that the question is really "asking directly for data" supports treating the dataset — which already holds the modelled data and measures — as the intended source.

Official Reference

These links open the official vendor documentation in a new tab.

Exam Strategy

Scan for two signals in PL-300 scenario questions: an artefact that already exists (a published report, dataset or semantic model) and a requirement to 'minimize development effort'. When both appear, the answer is almost always to reuse the existing Power BI dataset so existing measures and transformations carry over.

Frequently Asked Questions

Why is the SharePoint folder wrong if the Excel file lives there?

Pointing at the SharePoint folder creates a fresh model, so the cleansing steps and measures must be rebuilt. The published dataset already contains them.

Does the new report need its own copy of the measures?

No. Reports built on a Power BI dataset share that dataset's model, so all existing DAX measures are available immediately without duplication.

More PL-300 FAQ →

Community Votes

A
62%
B
18%
D
20%

62% of anonymous learners picked answer A. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 117 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 30 of 117

  1. Nomios 👍 147
    It should be dataset, because the case states there is already a report published and the datamodel contains measures. therefore and to be able to use the measures in the datamodel you should connect to the existing dataset (which was created when you plublished the report) instead of starting from scratch with the files in the SharePoint folder.
  2. rashjan 👍 26 Answered A
    reuse the existing dataset.
  3. TopCat1583 👍 11
    B is the correct answer. you have to take the data from the data source. How is a data set in power BI a data source? The data source is the excel document.
  4. Hoeishetmogelijk 👍 10
    The question is confusing because it doesn't tell clearly that there are two reports. So the second report can reuse the dataset of the first one.
  5. ZSun 👍 8
    I think the question is clear: Publish the first report, and then create the second report from dataset of the first report
Show 25 more comments
  1. Uhoh 👍 7 Answered B
    The question is: "Which type of data source should you use?" The Power BI dataset is NOT a data source. https://learn.microsoft.com/en-us/power-bi/connect-data/desktop-data-sources Thus, since it should have minimal developing impact, it should be answer B "Sharepoint folder".
  2. Green13 👍 7
    The answer is Sharepoint folder. The data model was for the previously published PowerBi report. Creating a new report from existing data refers to all Sales data on the sharepoint folder.
  3. visionary4ever 👍 5 Answered A
    A. Power BI dataset The Power BI dataset would be the best option in this scenario. If you've already published a Power BI report that imports data from an Excel file located in SharePoint and the data model contains several measures, you can simply use the existing Power BI dataset to create a new report. This would significantly minimize the development effort as you wouldn't need to import and transform the data again or recreate the measures. In Power BI Desktop, you can select "Power BI Datasets" as your data source and then select the published dataset you want to use. This method allows you to create multiple reports from a single dataset, enabling dataset reusability and consistency across reports. Options B, C, and D would require additional data loading and transformation efforts, which are not necessary in this case as the dataset has already been created and published.
  4. srikanth923 👍 5 Answered A
    The answer is A. Although there are two possible answers, if you use Power BI datasets, any data cleaning steps applied and measures created in the dataset will be automatically applied when the dataset is imported. However, if you import the dataset into Power BI using the SharePoint folder, you'll need to apply the data cleaning steps again, which requires more development work.
  5. NatRob 👍 5
    After reading the question multiple times, the biggest takeaway is that its asking directly for data. A SharePoint folder HOLDS data, but it is not data itself. I agree with this and think its the existing dataset
  6. saurinkhamar 👍 5
    B. a SharePoint folder as a datasource. Dataset is not a datasource. Dataset supports multiple datasources.
  7. Hoeishetmogelijk 👍 4 Answered A
    I read this question case like this: 1. You publish a Power BI report with its dataset including measures 2. You create a second Power BI report using the existing data with a minimal of effort. So my conclusion would be to reuse the dataset that was published together with the first report. So answer A.
  8. Briarheart1096 👍 4
    This Question appeared in the Mock Exam provided in Coursera Power BI course and has Sharepoint Folder as the correct answer. Even though i think it should be Dataset
  9. xxfangxx 👍 4 Answered A
    "You need to create a Power BI report from the existing data." the keywords here is "EXISTING DATA"
  10. chelchoul 👍 4
    Power BI dataset is litteraly the 2nd option of your link. Answer is A
  11. Dr_Do 👍 4 Answered A
    Several measures to be reused --> Dataset
  12. d94949999 👍 4 Answered B
    I think B is the right answer
  13. MBA_1990 👍 4 Answered A
    reuse of existing data
  14. omath 👍 3 Answered A
    A. Power BI dataset We already published a Power BI report with an imported model and measures. The easiest way to create another report using the same data and calculations (while minimizing development effort) is to connect to the existing Power BI dataset. This avoids rebuilding the model or measures from scratch. B. SharePoint folder → Would require recreating the model and measures. C. Power BI dataflows → Useful for ETL, but you’d still need to build the model again. D. Excel workbook → Same issue as SharePoint; more work to replicate measures.
  15. TopCat1583 👍 3
    B- I say SharePoint folder. The data source is Excel file nested in the SharePoint folder. I have several report deriving from one data source(excel inside a SP folder) in my job now. Think this way the data source is imported to Power BI, key work imported meaning the information is saving in Power BI but not updating. How will the imported Power BI data set update when the Excel file updates. It will not upddate?
  16. RooneySmith 👍 3 Answered B
    Option A is possible choice, but you may be encountered to an error message saying "DirectQuery isn't available for this dataset", then it would add development effort. This is why B is safer as there is no difference in the process between choosing a dataset or Sharepoint folder. It would increase the load time, but there is no development effort behind it.
  17. Masamune1 👍 3 Answered A
    Without a shadow of a doubt, if we want to create a report in PowerBI from a data model that contains measurements, we need to connect directly to that model, so we will use the Power BI Datasets option, if we connected to a Sharepoint folder , we would start from an excel file and nothing could be reused from the data model and its measurements.
  18. Lavoisier 👍 3
    The question is to select the type of data source. The answer can't be A, because Power Bi dataset is not a type of data source. The answer is B. SharePoint Folder is a type of data under the category File data source. Ref: https://learn.microsoft.com/en-us/power-bi/connect-data/desktop-data-sources
  19. Nagarajutd15 👍 3
    Answer is "A --> Power BI dataset" because the question says "You need to create a Power BI report from the existing data. The solution must minimize development effort." If we use power bi dataset the development efforts will be less.
  20. zak2003 👍 3
    To reuse the existing imported data, we use PBI Dataset resource. Refer >>> https://learn.microsoft.com/en-us/power-bi/connect-data/service-datasets-discover-across-workspaces
  21. Acrious 👍 3 Answered A
    It states that it already imported the data from an excel file for an existing report. You are now adding another report that uses the same data. So you just use the dataset
  22. LemonYeti 👍 3
    The key word here was "publish", in order to access datasets they need to be published first therefore the answer is A.
  23. Lkra1 👍 3 Answered B
    Its a sharepoint folder, we are specifically being told that the data is in a SharePoint location
  24. Migs123 👍 3 Answered B
    The first two sentences were meant to confuse you. The actual question is which "data source"
  25. Saluk_DE 👍 3 Answered A
    The set is already done and contains measures. You can build a report on the same dataset.

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