Creating a unique key within a data pipeline is essential for reliably identifying individual records, especially in scenarios where the source dataset lacks a natural primary key and where record traceability is required in later stages of processing. In distributed processing frameworks like Apache Spark, which operate in-memory and leverage…

Unlike traditional structured query databases, the difference between union and unionAll in Spark is unusual and not very intuitive. Below is the exercise, Two dataframes created with some of duplicate values. Ideally, in any traditional database union removes the duplicates from both the dataset (ie table) and returns only unique…