Use the aggregated positions and ages from ARRAY_AGG as input to ARRAY_TO_JSON to obtain a JSON object.
The example uses the table(s) created earlier.
SELECT pos, ARRAY_TO_JSON(ARRAY_AGG(age ORDER BY empId, NEW intarr5())) FROM employeeTable GROUP BY pos ORDER BY pos;
Result:
pos ARRAY_TO_JSON(ARRAY_AGG(…)) --------------------------------------- engineer [24,34,25,21] executive [50,51,52,52,60] manager [40,41,45,48] salesman [31,32,33,40]