We have two datasets containing sales records. The first data set has sales records from 2008 to beginning of 2011. The second dataset has additional sales records for 2011 only. Each record is a sale with date, price, etc ... We want to put the two datasets together keeping the same structure, just piling up sales from 2008-2011 and sales from 2011 only. To do that we use the Concatenate node. The structure of the two datasets is slightly different. The first dataset has a column "card" which the second dataset does not have. In comparison, the second dataset has a column "insurance" which the first dataset doies not have. An interesection of columns will exclude these two columns. A union of columns will include both columns filling the missing part with missing values