github.com/matrixorigin/matrixone@v1.2.0/test/distributed/cases/function/func_aggr.result (about)

     1  drop table if exists t1;
     2  CREATE TABLE t1 (id int(11),value1 float(10,2));
     3  INSERT INTO t1 VALUES (1,0.00),(1,1.00), (1,2.00), (2,10.00), (2,11.00), (2,12.00), (2,13.00);
     4  select id, stddev_pop(value1)  from t1 group by id;
     5  id	stddev_pop(value1)
     6  1	0.816496580927726
     7  2	1.118033988749895
     8  select id, variance(value1)  from t1 group by id;
     9  id	variance(value1)
    10  1	0.6666666666666666
    11  2	1.25
    12  drop table t1;
    13  drop table if exists t;
    14  CREATE TABLE t(txt char(1), i INT);
    15  INSERT INTO t VALUES ('a', 2), ('b', 8), ('b', 0), ('c', 2);
    16  SELECT txt, STDDEV_POP(i) s FROM t GROUP BY txt ORDER BY s, txt;
    17  txt	s
    18  a	0.0
    19  c	0.0
    20  b	4.0
    21  drop table t;