-Re: CONCAT(null, "something") == NULL ?
Yang 2012-11-05, 17:15
thanks guys, now I see that returning NULL makes sense
On Fri, Nov 2, 2012 at 3:40 PM, Cheolsoo Park <[EMAIL PROTECTED]> wrote:
> Hi Alan,
> Recently, I have seen several similar confusions about nulls in Pig. For
> example, here is another discussion:
> We are documenting them, but apparently, many users find it confusing. I am
> wondering if there is anything that we can do better.
> On Fri, Nov 2, 2012 at 3:33 PM, Alan Gates <[EMAIL PROTECTED]> wrote:
> > 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 should be "something" , right?
> > >
> > > but on my system it gave null