The table distribution key is another element that can influence the distribution of table rows across existent partitions defined in a database partition group. Distribution keys can be created explicitly using DISTRIBUTION BY HASH (columns) directive inside table definition or they can be defined implicitly by DB2 using a series of column rules detailed in this recipe. Usually distribution column might be designed and used to improve query performance.
This recipe is strongly correlated with the preceding one; here, we will also use before and after pictures of how the data is distributed across database partitions.