A RowFunction must implement operateOnSomeRows(), while a PartitionFunction must implement operateOnPartition(). The only difference between the two is that operateOnPartition() includes an argument that describes the current partition. Both these functions are given a RowIterator, which allows iteration through all the rows that the function sees. Moreover, they are provided with a RowEmitter, which allows the function to returns rows to the database.
Below is an example of a simple function that tokenizes its input into rows. This example and the rest of the examples in this section are part of the Aster SQL-MapReduce SDK bundle.