Question About Dataset Mode - Import or Composite

[Anonymous]

This is a question coming from PL-300 practice test. There are two data sources to be used:

And here are the report requirements:

• Report data must be current as of 7 AM Pacific Time each day.
• The reports must provide fast response times when users interact with a visualization.

The question is asking which dataset mode should use to create the dataset with the following choices:
A. Import
B. DirectQuery
C. Composite
D. live connection

Personally I think A because of the report requirements - It won' t have that 7AM stamp and fast response time if we use directquery. However as I know the PBIX size limitation for non-premium account is 1GB, while the Azure SQL database has 2GB...so I am not sure if I should go with A (use import for Azure SQL DB) or C (use directquery for Azure SQL DB). Could someone help to explain which answer is correct?

Thank you!

[Anonymous · Accepted solution]

Hi @Anonymous ,

Thanks for the reply from @rajendraongole1 , please allow me to provide another insight:

If by 2GB you mean its size in the data source, you can be pretty sure that the size of the dataset will be smaller than the size of the data in the data source, but it can only be a little bit smaller, or it can be much smaller, maybe even just 10-20% of the original size. This is because Power BI compresses the data very effectively when importing it. What's more, how the data is modelled can have a significant impact on how well it is compressed, and making a few changes can result in a much smaller dataset.

Therefore, install a free, community-developed tool called DAX Studio: its model metrics feature shows the total size of the dataset on the Summary tab. If it is less than 1GB then consider using import mode.

More details can be found at: Chris Webb's BI Blog: How Much Data Can You Load Into Power BI? (crossjoin.co.uk)

If your Current Period does not refer to this, please clarify in a follow-up reply.

Best Regards,

Clara Gong

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

[rajendraongole1]

Hi @Anonymous - As per the questin, 

Given the need for current data as of 7 AM each day and fast response times, the best approach would likely be Composite Mode (C). This allows you to import the smaller Excel Spreadsheet, ensuring fast query performance for that data.Use DirectQuery for the larger Azure SQL Database, allowing you to meet the requirement for the latest data without hitting the size limitation.

This approach will help you balance the need for up-to-date data with performance considerations. If you are on a non-premium account, this method will help you avoid the 1 GB size limitation for Import mode by leveraging DirectQuery for the larger dataset.

Hope the above explaination helps

Did I answer your question? Mark my post as a solution! This will help others on the forum!
Appreciate your Kudos!!

[Anonymous]

Thanks for the reply! @rajendraongole1 

But if I use DirectQuery for Azure SQL Database, the report time might not show as 7 AM each day isn't it? Because it shows data in real-time? Please correct me if I am wrong. Thanks!