When grouping Dataset into Spark, there are two methods: groupBy and groupByKey[K] .
groupBy returns a RelationalGroupedDataset , and groupByKey[K] returns a KeyvalueGroupedDataset .
What are the differences between the two?
Under what circumstances should I choose one after another?
Why is my question a duplicate of these Dataset vs DataFrame questions? I do not understand. These are completely different things! My question is very specific, but not general.
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