Apache Spark Join Expression

A join brings together two sets of data. Spark compares the value of one or more keys of the left and right data and evaluates a join expression to decide whether it should bring the left set of data and the right set of data. The join expression determines where the two rows should join and the join type determines what should be the result. If you are interesting in Apache Spark please contact us for more information.

Inner Joins
Inner Joins

Inner Joins

Keeps rows that exist in both datasets

Outer Join
Outer Join

Outer Join

Keeps rows with keys in either dataset

Left Outer Join
Left Outer Join

Left Outer Join

Keeps rows with keys in left the dataset

Right Outer Join
Right Outer Join

Right Outer Join

Keeps rows with keys in right the dataset

PySpark Join Syntax

Apache Spark Join Expression
Apache Spark Join Expression
Inner Join
Outer Join
Left Outer Join
Right Outer Join

For Example:

rc.join(ps, rc.District = ps.Format_district, ‘left_outer’).show()
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