UDF在红移中:可以在另一个中引用udf

时间:2016-03-11 10:36:56

标签: user-defined-functions amazon-redshift tableau udf

是否可以将UDF嵌套在彼此之内?

以下是在A / B测试中计算置信区间的代码 - 当然,我可以编写一个功能齐全的大功能,但想知道实现这一目标的更好方法吗?

set search_path to public;
create function cumnormdist(x float)
  returns float
IMMUTABLE AS $$
  import math
  b1 = 0.319381530
  b2 = -0.356563782
  b3 = 1.781477937
  b4 = -1.821255978
  b5 = 1.330274429
  p = 0.2316419
  c = 0.39894228
  h=math.exp(-x * x / 2.0)
  if(x >= 0.0) :
    t = 1.0 / ( 1.0 + p * x )
    return (1.0 - c * h * t *( t *( t * ( t * ( t * b5 + b4 ) + b3 ) + b2 ) + b1 ))
  else :
    t = 1.0 / ( 1.0 - p * x );
    return ( c * h * t *( t *( t * ( t * ( t * b5 + b4 ) + b3 ) + b2 ) + b1 ))
$$ language plpythonu;


set search_path to public;
create or replace function conversion(experience_total float,experience_conversions float)
  returns float
IMMUTABLE AS $$
  return experience_conversions*1.0/experience_total
$$ language plpythonu;


create or replace function zscore(total_c float,conversions_c float,total_t float,conversions_t float )
  returns float
IMMUTABLE AS $$
  import math
  z = conversion(total_t,conversions_t )-conversion(total_c,conversions_c) # Difference in means
  s =(conversion(total_t,conversions_t)*(1-conversion(total_t,conversions_t)))/total_t+(conversion(total_c,conversions_c)*(1-conversion(total_c,conversions_c)))/total_c
  return float(z)/float(math.sqrt(s))
$$ language plpythonu;

create or replace function confidence(total_c float,conversions_c float,total_t float,conversions_t float )
  returns float
IMMUTABLE AS $$
  import math
  return **(1-float(cumnormdist(zscore(total_c float,conversions_c float,total_t float,conversions_t float )),4))*100.00**
$$ language plpythonu;

个人通话工作正常,例如:select cumnormdist (-3.1641397476); 如果我在功能定义中插入它们,则不会,例如调用转换功能的zscore。

ERROR:  NameError: global name 'zscore' is not defined. Please look at svl_udf_log for more information
DETAIL:  
  -----------------------------------------------
  error:  NameError: global name 'zscore' is not defined. Please look at svl_udf_log for more information
  code:      10000
  context:   UDF
  query:     0
  location:  udf_client.cpp:298
  process:   padbmaster [pid=3585]
  -----------------------------------------------

如果我可以将函数嵌套在彼此内部(而不是像上面那样最终嵌套的UDF),这将是一个合理的状态

结束目标:在Tableau中发布这些计算。

1 个答案:

答案 0 :(得分:2)

以下是我如何解决它。 UDF无法交叉引用另一个UDF的内容,因此您可以创建自定义库,使用CREATE库将其上载到AWS。

More here