Summe in Apache Schwein: Fehler 1045

Question

Ich möchte eine Abteilung von 2 Summen berechnen Schwein mit

A = LOAD 's3://input' AS (filed1:chararray, filed2:int, field3:float, field4:float); 
filtered_1 = FILTER A BY field3 >= 10; 
filtered_2 = FILTER filtered_1 BY field4 >= 50; 
grouped = GROUP filtered_2 BY field1; 
B = FOREACH grouped GENERATE group as field1, SUM(A.field3)/SUM(A.field4) AS A_avg; 

außer ich diesen Fehler haben während des letzten Befehl:

ERROR grunt.Grunt: ERROR 1045: <line 5, column 55> Could not infer the matching function for org.apache.pig.builtin.SUM as multiple or none of them fit. Please use an explicit cast. 

Und ich kann nicht finden, warum seit ich GROUP benutze, bevor ich meine Summe ausgeführt habe, und ich bin durch das SUM-Dokument gegangen und ich weiß nicht, was sich mit dem, was ich geschrieben habe, unterscheidet

Answer 1

grouped = GROUP filtered_2 BY field1; 

grouped has no ACCESS to alias A . 

B = FOREACH grouped GENERATE group as field1, SUM(A.field3)/SUM(A.field4) AS A_avg; 

"FOREACH grouped " has no access to alias A but directly to fields (field3, field4) 






filtered_1 = FILTER A BY field3 >= 10; 
filtered_2 = FILTER filtered_1 BY field4 >= 50; 


All you are doing in this statement is an AND operation 

filtered_3 = FILTER A BY field3 >= 10 AND field4 >= 50; 

Now 
grouped = GROUP filtered_3 BY field1; 
B = FOREACH grouped GENERATE group as field1, SUM(filtered_3.field3)/SUM(filtered_3.field4) AS A_avg;