Data Engineering Associate with Databricks Practice Exam

In PySpark, what is the correct method to initiate a write stream?

1. Spark.table().writeStream()

2. Spark.writeStream().table()

3. Spark.table().writestream()

4. Spark.stream().write()

The correct answer is: Spark.table().writestream()

The correct method to initiate a write stream in PySpark is found in the combination of data source followed by the writeStream function. Specifically, the command `Spark.table().writeStream()` is the proper way to initiate a stream write operation on a DataFrame that is created from a table in Spark. In this method, `Spark.table()` retrieves data from a specified table and transforms it into a DataFrame. The `.writeStream()` method allows you to configure the streaming write operation on that DataFrame, enabling you to define how you want to write the data out. Each of the other choices misplaces the appropriate use of the methods or their sequencing, which is essential to successfully initiating a write stream. For instance, Spark.writeStream() is intended for starting a new write stream context, but it must be called in conjunction with a DataFrame that is representing the data, which is achieved with methods like Spark.table(). Moreover, the capitalization in Spark.stream() and writestream does not match the correct case sensitivity of the PySpark API, rendering those options invalid. Understanding these details is essential for correctly implementing streaming operations in PySpark.