You have folders and files in Azure Blob Storage for the Azure Synapse. You develop a native external table “EtTable1” with LOCATION=’/webdata/’. If you query EtTable1 with Azure Synapse Analytics Serverless SQL POOL, choose from the following files that will be returned?

Answer options:

A.Only mydata.txt
B.Only mydata2.txt
C.Only mydata3.txt
D.mydata.txt, mydata2.txt, and mydata3.txt
E.Only _hidden.txt
F.All of these i.e mydata.txt, mydata2.txt, mydata3.txt and _hidden.txt

Correct Answer: A 
You have folders and files in Azure Blob Storage for the Azure Synapse workspace just like the below diagram: 

If you want to return subfolders from Native external tables,you need to mention /** at the end of the path. In the given case scenario, LOCATION=`/webdata/`will make the query to return only mydata.txt, not mydata2.txt and mydata3.txt as these both files exist in the subfolders. On the other hand, A Hadoop table returns all files within any subfolder. 
Both Native and external tables skip the files with the names beginning with a period (.) or an underline (_). Therefore, it won’t return _hidden.txt as well.
Option A is correct. In the given Scenario, the only mydata.txt will be returned.
Option B is incorrect. mydata2.txt won`t be returned as it is present in the subfolder and the location does not involve /** at the end.
Option C is incorrect. mydata3.txt won`t be returned as it is present in the subfolder and the location does not involve /** at the end.
Option D is incorrect. The only mydata.txt will be returned.
Option E is incorrect. Both Native and external tables skip the files with the names beginning with a period (.) or an underline (_). Therefore, _hidden.txt won’t be returned.
Option F is incorrect. In the given Scenario, the only mydata.txt will be returned.
Reference: 
To know more about using external tables with Synapse SQL, please visit the below-given link: 

https://docs.microsoft.com/en-us/azure/synapse-analytics/sql/develop-tables-external-tables?tabs=hadoop