How to work with MapReduce Key Value Pairs in Pentaho Data IntegrationMy main objective for this article is to provide you an understanding on how to use multiple fields to group by and multiple fields to aggregate on in Pentaho PDI MapReduce.The input key for the mapper is auto-generated, the value is usually the line of text which is read in (fields separated by comma in example). This section here will focus on the output key value pair of the...
