Scala and Spark for Big Data Analytics

Join types

The following is a table of the different types of joins. This is important, as the choice made when joining two datasets makes all the difference in the output, and also the performance.

Join type	Description
inner	The inner join compares each row from left to rows from right and combines matched pair of rows from left and right datasets only when both have non-NULL values.
cross	The cross join matches every row from left with every row from right generating a Cartesian cross product.
outer, full, fullouter	The full outer Join gives all rows in left and right filling in NULL if only in right or left.
leftanti	The leftanti Join gives only rows in left based on non-existence on right side.
left, leftouter	The leftouter ...