Re: Possible bug in NULL fields handling

[Vincent BARAT]

Thank you very much for your answer!
I was not aware about the COUNT_STAR() function.
I guess it has been introduced recently (otherwise it is a bug in 
the documentation :-)

Anyway, the end proposal in PIG-1014 seems ok to me. At least, I 
think that the current behavior of the COUNT when applied on bags is 
misleading.

Dmitriy Ryaboy a écrit :
Currently, COUNT of a bag will ignore bags which have the first field
as null (this stems from the fact that COUNT of a column will count
non-null columns, for sql compatibility). You may want to try using
COUNT_STAR. This behavior is currently being reconsidered:
https://issues.apache.org/jira/browse/PIG-1014 (please provide input!)

-Dmitriy

On Thu, Oct 15, 2009 at 8:51 AM, Vincent BARAT <vincent.ba...@ubikod.com> wrote:
Hello,

I'm not sure if it's a bug, but the handling of NULL fields seems not to
work correctly:

My data (events):

0,,jawi
,0,juug
,,lfou
0,0,caro

My script:

events = load 'events' using PigStorage(',') AS (sessionid:chararray,
jobid:chararray, user:chararray);
user_events = group events by user;
dump user_events;
event_count_by_user = foreach user_events generate group, COUNT(events);
dump event_count_by_user;

The results:

user_events (correct):
(caro,{(0,0,caro)})
(jawi,{(0,,jawi)})
(juug,{(,0,juug)})
(lfou,{(,,lfou)})

event_count_by_user (incorrect):
(caro,1L)
(jawi,1L)
(juug,0L)
(lfou,0L)

event_count_by_user should be:

(caro,1L)
(jawi,1L)
(juug,1L)
(lfou,1L)

It seems that tuples starting with (, are not counted correctly.

Any suggestion?

Thanks a lot