Which statement describes the execution and results of running the above query multiple times?

A junior data engineer seeks to leverage Delta Lake’s Change Data Feed functionality to create a Type

1 table representing all of the values that have ever been valid for all rows in a bronze table created with the property delta.enableChangeDataFeed = true. They plan to execute the following code as a daily job:

Which statement describes the execution and results of running the above query multiple times?
A . Each time the job is executed, newly updated records will be merged into the target table, overwriting previous values with the same primary keys.
B . Each time the job is executed, the entire available history of inserted or updated records will be appended to the target table, resulting in many duplicate entries.
C . Each time the job is executed, the target table will be overwritten using the entire history of inserted or updated records, giving the desired result.
D . Each time the job is executed, the differences between the original and current versions are calculated; this may result in duplicate entries for some records.
E . Each time the job is executed, only those records that have been inserted or updated since the last execution will be appended to the target table giving the desired result.

View Answer

Answer: B

Explanation:

Reading table’s changes, captured by CDF, using spark.read means that you are reading them as a static source. So, each time you run the query, all table’s changes (starting from the specified startingVersion) will be read.