/* finding nearest neighbors for person with age 55 
and working hours per week 48, 
and 2 educations numeric - 8(HS) or 17(bachelor) and married*/
SELECT neighbors.salarylevel, count (*) FROM
(SELECT salarylevel, ((age - 55)*(age - 55) + (workinhoursperweek - 48)*(workinhoursperweek - 48)
+(educationnumeric - 17)*(educationnumeric - 17)+
(CASE WHEN maritalstatus='Married-civ-spouse' THEN 0 ELSE 1 END)) as distance
FROM person
ORDER BY 2
LIMIT 35) neighbors
GROUP BY neighbors.salarylevel;