I agree with Alan on all counts. I think the confusing part is that null is
overloaded. Alas.
2012/11/5 Alan Gates
> Better in terms of semantics or terms of documentation? We can't change
> the semantics of null in Pig; it's been that way the whole time. Plus this
> concept of unknown data i
Better in terms of semantics or terms of documentation? We can't change the
semantics of null in Pig; it's been that way the whole time. Plus this concept
of unknown data is important in data processing. If we had it to do over again
we could name it 'unknown' instead of null, but it seems la
thanks guys, now I see that returning NULL makes sense
On Fri, Nov 2, 2012 at 3:40 PM, Cheolsoo Park wrote:
> Hi Alan,
>
> Recently, I have seen several similar confusions about nulls in Pig. For
> example, here is another discussion:
> https://issues.apache.org/jira/browse/PIG-3021.
>
> We a
Hi Alan,
Recently, I have seen several similar confusions about nulls in Pig. For
example, here is another discussion:
https://issues.apache.org/jira/browse/PIG-3021.
We are documenting them, but apparently, many users find it confusing. I am
wondering if there is anything that we can do better.
To give some context, the null semantics in Pig follow SQL's. In SQL, null is
viral, so any operation with null results in null. The idea is that null means
unknown, not empty. So concat('x', unknown) = unknown.
Alan.
On Nov 2, 2012, at 3:09 PM, Yang wrote:
> looks a more intuitive result s
Hi,
You're not the only one who finds it not intuitive. Please see:
https://issues.apache.org/jira/browse/PIG-2929.
Thanks,
Cheolsoo
On Fri, Nov 2, 2012 at 3:09 PM, Yang wrote:
> looks a more intuitive result should be "something" , right?
>
> but on my system it gave null
>
