Cleaning up temporary Data Extensions

are old temporary data extensions created by deselect keeping storage on sfmc? if so, then read up! note starting may 2025, all newly created selections are automatically subject to the retention policy this ensures that all associated preview and de duplication data extensions (des) are automatically deleted, optimizing storage usage without requiring manual intervention for data extensions created before june 2025, this automated cleanup process does not apply these pre existing des must be manually deleted to free up storage space what are temporary data extensions temporary data extensions are internally generated by deselect in the following scenarios using the run preview feature when you preview a selection, deselect stores the preview results in a temporary data extension to ensure that the target data extension remains unaffected once you run the selection after previewing, the temporary data extension is automatically deleted using prio deduplication in this case, deselect creates two temporary data extensions the first data extension runs the selection as usual, while the second applies the deduplication rules how to work with temporary data extensions? all the temporary data extensions are being stored under deselect folder in sfmc data extensions if the list of temporary data extensions piles up, you might want to do some cleaning some best practices when working with temporary data extensions would be the following set the correct data retention policy for temporary des in the admin panel by making use of this feature, the temporary de will be automatically deleted after a selected period of time delete old selections that you don't need anymore, as it will delete the temporary data extensions related to it clean up existing temporary data extensions, based on the lastmodifieddate older temporary data extensions have fewer chances of being in use, so you can start by deleting the older ones note that even after deleting the temporary data extensions, the selections related to them will still be accessible and will work perfectly