How do I select all id's that are present in one table but not in another

I am trying to get a list of department Ids are present in one table, (PS_Y_FORM_HIRE), but which don't exist in another table (PS_DEPARTMENT_VW). Here is the basics of what I have which isn't working: SELECT h.DEPTID FROM PS_Y_FORM_HIRE h, PS_DEPARTMENT_VW d WHERE NOT EXISTS ( SELECT d1.DEPTID FROM PS_DEPARTMENT_VW d1 WHERE d1.DEPTID = h.DEPTID and d1.SETID_GL_DEPT = 'IDBYU' ); I'm trying to form this query in SQL Developer, but it just returns a long list of blanks (after spinning/running the query for a very long time). In addition, I need this to be effective dated, so that it only grabs the correct effective-dated row, but I was unsure how and where to incorporate this into the query. Also note that DEPTID isn't a key on PS_Y_FORM_HIRE, but is on PS_DEPARTMENT_VW. (Along with SETID_GL_DEPT and EFFDT). So again, ideally, I will have a list of all the department ids that appear in PS_Y_FORM_HIRE, but which are not in PS_DEPARTMENT_VW.