In Apache Spark, the DataFrameWriter API is used to save a DataFrame to an external storage system. To overwrite existing data, the save mode must be set to "overwrite".

Option A uses the standard method chaining: df.write returns a DataFrameWriter, .mode("overwrite") sets the desired save behavior, and .json("path/to/file") specifies the format and path, triggering the write operation.

Option D uses the generic .save() method. Here, .format("json") specifies the data source type, and the mode="overwrite" argument is passed directly into the .save() method, achieving the same result. Both are valid and documented ways to perform an overwrite operation.

B. df.write.overwrite.json("path/to/file")

The DataFrameWriter API does not have a direct .overwrite method or attribute; the save mode is set exclusively using the .mode() method or as a parameter to .save().

C. df.write.json("path/to/file", overwrite=True)

The format-specific .json() method does not accept an overwrite boolean parameter. Save modes must be configured using the .mode() method prior to the write call.

1. Apache Spark 3.5.1 Official Documentation

pyspark.sql.DataFrameWriter:

For Option A: The documentation shows the mode(saveMode) method

which sets the SaveMode

and the json(path

...) method

which saves the content in JSON format. The standard usage is to chain these: df.write.mode('overwrite').json(path).

For Option D: The documentation for the save(path=None

format=None

mode=None

...) method explicitly lists mode as a parameter. This confirms that df.write.format('json').save(path

mode='overwrite') is a valid syntax.

For Options B and C: The API documentation confirms the absence of a .overwrite method and an overwrite parameter within the .json() method

invalidating these options.

2. Databricks Official Documentation

"Read and write JSON files":

The documentation provides examples for writing data. The standard syntax shown for overwriting is df.write.mode("overwrite").json("/tmp/my-json-file")

which directly supports the correctness of Option A. It also explains the different save modes

including overwrite.