Are UNIONs supported in DESelect Segment?

question are unions supported in deselect segment? answer yes, in deselect segment you can work with append data extensions (using different tabs as sources) each tab is a query, and the different tabs are added together with one unions statement create a new tab by clicking on the + add new source icon on the left side of the screen example you can use append data extension if you want to add rows of multiple data extensions together for instance you have 4 data extensions with contact information (first name, last name, email), and want to create one new data extension that contains the contacts in these 4 data extensions you will create a tab for each of the data extensions, and your target data extension will contain the rows of all 4 data extensions matching the filters in the respective tabs