text: -- @testpoint: 聚集函数var_samp，入参为浮点数
  
  drop table if exists t_nvl_rca_tab;
  create table t_nvl_rca_tab(col_1 NUMERIC(10,4));
  insert into t_nvl_rca_tab values(123456.123);
  insert into t_nvl_rca_tab values(123454.12354);
  select var_samp(col_1) from t_nvl_rca_tab;
  drop table if exists t_nvl_rca_tab;
  