You are working on Azure Data Lake Store Gen1
Suddenly, you realize the need to know the schema of the external data.
Which of the following plug-in would you use to know the external data schema?
Click on the arrows to vote for the correct answer
A. B. C. D. E.Correct Answer: E.
Option A is incorrect.
The ipv4_lookup plugin checks for an IPv4 value in a lookup table and returns the matched rows.
Option B is incorrect.
The mysql_request plugin transfers a SQL query to a MySQL Server network endpoint and returns the 1st row set in the result.
Option C is incorrect.
Pivot plug-in is used to rotate a table by changing the unique values from 1 column in the input table into a number of different columns in the output table and perform aggregations wherever needed on any remaining column values that are desired in the final output.
Option D is incorrect.
This plug-in is used to unpivot a wide table into a table with only three columns.
Option E is correct.
infer_storage_schema plug-in can be used to infer the schema of external data and return it as a CSL schema string.
References:
To know more about the external tables and plug-in, please visit the below-given link:
Among the given options, the plug-in that can be used to know the external data schema in Azure Data Lake Store Gen1 is "infer_storage_schema."
Infer_storage_schema is a U-SQL extractors library which can be used to automatically infer the schema of external data files in Azure Data Lake Store Gen1. This library extracts the schema information from the external data files and generates a C# script that can be used to create an external table for the data.
The schema inference is done based on the file format of the data files, such as CSV, TSV, JSON, Avro, Parquet, and ORC. When using the infer_storage_schema library, the file format of the external data files needs to be specified as an argument.
Once the schema of the external data is inferred, the resulting C# script can be used to create an external table in Azure Data Lake Store Gen1. This external table can then be used to query the data using U-SQL.
In conclusion, if you need to know the schema of external data in Azure Data Lake Store Gen1, you can use the infer_storage_schema plug-in to automatically infer the schema and generate a C# script for creating an external table.