2. DB = Database. 3. FIL = File. 4. IDX = Index/Object. 5. TAB = Table. 6. PAG = Page. 7. KEY = Key. 8. EXT = Extension. 9. RID = RID (Line ID).10. APP = Application.11. MD = METADATA.12. HBT = HOBT.13. AU = ALLOCATION_UNIT.