After you drop a dbspace, blobspace, or sbspace, the newly freed chunks are available for reassignment to other dbspaces, blobspaces, or sbspaces. However, before you reassign the newly freed chunks, you must perform a level-0 backup of the root dbspace and the modified storage space. If you do not perform this backup, and you subsequently need to perform a restore, the restore might fail because the backup reserved pages are not up-to-date.