Answer: CSV

## Detailed Explanation When using the OPENROWSET function in Azure Synapse Analytics to read JSON files from Azure Data Lake Storage, the correct FORMAT option is **CSV** (Option D), not JSON (Option A). ### Why CSV is the Correct Choice: 1. **OPENROWSET Function Limitations**: The OPENROWSET function in Azure Synapse Analytics does not have a native 'JSON' format option. The supported format values are: - 'CSV' for delimited text files - 'PARQUET' for Parquet files - 'DELTA' for Delta Lake format 2. **JSON File Processing Workaround**: To read JSON files using OPENROWSET, you must use the CSV format with specific delimiter configurations: - Set `FORMAT = 'CSV'` - Configure `FIELDTERMINATOR = '0x0b'` (vertical tab character) - Configure `FIELDQUOTE = '0x0b'` - For multi-line JSON files, also set `ROWTERMINATOR = '0x0b'` 3. **Achieving Single JSON Record per Rowset**: This configuration ensures that each JSON document is treated as a single field/row, meeting the requirement that "each rowset contains a single JSON record." 4. **Microsoft Documentation Support**: Official Microsoft documentation explicitly states that JSON files should be read using the CSV format with the specified delimiter settings. ### Why Other Options Are Incorrect: - **Option A (JSON)**: This format is not supported by the OPENROWSET function in Azure Synapse Analytics and will result in an error. - **Option B (DELTA)**: This is for Delta Lake format files, not JSON files. - **Option C (PARQUET)**: This is for Parquet binary files, not JSON text files. ### Recommended Implementation: ```sql SELECT doc FROM OPENROWSET( BULK 'https://storage1.dfs.core.windows.net/container1/folder1/*.json', FORMAT = 'CSV', FIELDTERMINATOR = '0x0b', FIELDQUOTE = '0x0b', ROWTERMINATOR = '0x0b' ) WITH (doc NVARCHAR(MAX)) AS rows ``` This approach correctly processes JSON files while ensuring each rowset contains a single JSON record as required.

Author: LeetQuiz Editorial Team