Добавить дополнительные столбцы в уже существующий столбец

Question

Есть ли способ добавить дополнительные столбцы в уже существующую таблицу? например, добавление дополнительных столбцов user который null для всех строк и столбцов date набор для 2015-02-01

serial:long, title:chararray, year:int,score:float 
(49586,Winter Wonderland,2013,2.8) 
(49587,Top Gear: Series 19: Africa Special,2013,3.1) 
(49588,Fireplace For Your Home: Crackling Fireplace with Music,2010,7.3) 

grunt> 
serial:long, title:chararray, year:int,score:float,user:long,date:chararray 
(49586,Winter Wonderland,2013,2.8, ,2015-02-01) 
(49587,Top Gear: Series 19: Africa Special,2013,3.1, ,015-02-01) 
(49588,Fireplace For Your Home: Crackling Fireplace with Music,2010,7.3, ,015-02-01) 

Answer 1

Можете ли вы попробовать это?

вход

49586,Winter Wonderland,2013,2.8 
49587,Top Gear: Series 19: Africa Special,2013,3.1 
49588,Fireplace For Your Home: Crackling Fireplace with Music,2010,7.3 

PigScript:

A = LOAD 'input' USING PigStorage(',') AS (serial:long,title:chararray,year:int,score:float); 
B = FOREACH A GENERATE serial,title,year,score, null AS (user:long) ,'2015-02-01' AS (date:chararray); 
DUMP B; 

Выход:

(49586,Winter Wonderland,2013,2.8,,2015-02-01) 
(49587,Top Gear: Series 19: Africa Special,2013,3.1,,2015-02-01) 
(49588,Fireplace For Your Home: Crackling Fireplace with Music,2010,7.3,,2015-02-01)