How does PowerBI read Append Blobs?

[tinkerbell]

1. I am reading data from a Azure Blob storage account into PowerBI. I am using append blobs to store my data. Data gets appended to the blobs periodically. Does PowerBI read all the data in the storage (based on the query) each time it refreshes? Or does it load the data incrementally (i.e. only the recent appends are read)? The total data to be stored will be in the order of ~100 GBs but the incremental data should be within ~1-2 GB so I would like to know how well my current model would scale. I went through the PowerBI security white paper but I wasn't able to find any information on this. 

2. Does reading from a Azure table storage give better performance than blob storage?

3. I read that the data model size should be less than 1 GB for uploading to the PowerBI service. When the dashboards refresh through the service, is there any limitation on the size of the data itself? My data model is within the 1 GB limit. 

[v-shex-msft · Accepted solution]

Hi @tinkerbell,

#1. Power bi will read all data.

#2. I'm not very familiar with azure datasource performance, perhaps you can submit this to azure forum for better support.

#3. There are a 10G data limit about gateway refresh, for detailed information, you can take a look at below link:

Power BI Gateway - Exced the limit.

Regards,

Xiaoxin Sheng