Exam PL-300 topic 2 question 101 discussion

Create aggregations to summarize results. This seems to be saying group and summarize after the data has come through the gateway as an import. This will not reduce the traffic as it has already come through the gateway. Answer : B.No.

Creating aggregations does not reduce the data sent through the gateway during a refresh. It helps runtime performance in reports, but not data transfer volume during import.

Explanation Import Mode Behavior: When a model is set to Import mode, the complete dataset is loaded into Power BI’s in‑memory engine during refresh. The on‑premises data gateway is used only at refresh time to pull data from the on‑premises source. Once the data is imported, all queries run against the local in‑memory copy in the service, not through the gateway. Role of Aggregations: Aggregations are designed to improve query performance—especially in composite models or DirectQuery scenarios—by pre‑calculating summarized data and reducing the need to hit detailed tables at query time. Why It Doesn’t Meet the Goal: In Import mode, even if you create aggregations, the full data refresh still occurs via the gateway. Aggregations do not affect how much data is transferred during a data refresh; they only reduce query processing time at runtime.

depends on where the aggregation is conducted. If it is done in power BI then the amount of data will still be the same. If the aggregation is done in the source then Yes

Yes, creating aggregations to summarize results reduces the amount of data sent through the on-premises data gateway by summarizing the data in the semantic model. Creating aggregation reduce querying time and compression.

You create aggregations in Power Query before importing data, soy you reduce de amount of data in the semantic model and in the gateway

creating aggregations reduces the amount of data sent through the gateway and optimizes data refresh and query performance.

It can't be B. If the data is imported and you then you aggregate (creating summarize tables) off the imported data, you are not reducing the overall model. You are actually increasing the size. While the summarize table would perform quicker, the original imported table with all the data remains. You need to reduce it at it's source before you bring in the data through import storage.

Aggregations allow you to precompute and store summarized data, which minimizes the need to load and query large amounts of detailed data. This approach is particularly beneficial in large DirectQuery or Import models:

not sure of question. you aggregate the results after importing? then the answer is no. if you are doing it before then the answer is yes

answer is yes. Aggregating ans summarizing reduces data.

The answer is A.