The saveAsTable method is specifically designed to write the contents of a DataFrame to a persistent table within the metastore. The question requires the operation to fail if the table already exists. This behavior is controlled by the SaveMode. The ErrorIfExists mode (which is the default) ensures that if the target table already exists, an AnalysisException is thrown, and the operation is aborted without any modification. This precisely matches the requirements of the scenario.

B. saveAsTable with mode Overwrite: This mode would drop the existing table and create a new one, which violates the requirement to fail and not modify anything.

C. save with mode Ignore: The save method writes data to a file system path, not a metastore table. Additionally, Ignore mode would silently do nothing if the path exists, instead of failing.

D. save with mode ErrorIfExists: The save method is incorrect because it does not create a managed table in the metastore; it only writes data to a file system path.

1. Apache Spark 3.4.1 Documentation

SQL

Data Sources

Load and Save Functions

Save Modes:

Section: "Save Modes"

Content: The documentation explicitly states for ErrorIfExists (default): "When saving a DataFrame to a data source

if data/table already exists

an exception is expected to be thrown." This confirms the failure behavior.

URL: https://spark.apache.org/docs/3.4.1/sql-data-sources-load-save-functions.html#save-modes

2. Apache Spark 3.4.1 Documentation

API for Scala

org.apache.spark.sql.DataFrameWriter:

Method: saveAsTable(tableName: String)

Content: The documentation for the DataFrameWriter class describes the saveAsTable method as the way to save the content of the DataFrame as the specified table. This distinguishes it from the save(path: String) method

which writes to a path.

URL: https://spark.apache.org/docs/3.4.1/api/scala/org/apache/spark/sql/DataFrameWriter.html#saveAsTable(tableName:String):Unit

3. Databricks Documentation

Create a table:

Section: "Create a table from a DataFrame"

Content: This page provides examples of creating tables using df.write.saveAsTable("tablename")

establishing it as the correct method for the task. It also links to save options

including the different modes.

URL: https://docs.databricks.com/en/tables/create.html#create-a-table-from-a-dataframe