In course DA450 - Apache pig, slide guide page 60, there are relations explaining how to get count of all the rows. I am finding it difficult understand this.
I could understand UNIQUE = DISTINCT ROTHERA; but after this relation below relation is something i am finding it difficult to understand.
unique_count = foreach (group UNIQUE all ) generate COUNT(unique);
What is the significance of brace around group operation?
what is "all" in group operator?
Could somebody please help understand?