IsEmpty simply checks whether the bag has elements or not (I got your
question wrong, I think this happens too often to me now :)
I don't think there is such a UDF for your use case yet. Would your UDF
work for muti-element tuples as well?
r1: {(a,e), (b,f), (c,g)}, (b,f)
As Dmitriy suggested, great if you can contribute this back.
On Mon, Feb 13, 2012 at 2:44 PM, Flo Leibert <[email protected]>wrote:
> Thanks for the responses, I think Dmitriy has the right answer as even
> after digging through lots of Pig JavaDocs, there doesn't seem to be a
> containment clause.
>
> I need the following:
>
> r1: {(a), (b), (c)}, (b)
> r2: {(z), (c)}, (f)
> r3: {(a)}, (a)
>
> I want to filter based on Bag B CONTAINS Tuple T, i.e. in this case I'd
> only be interested in r1 & r3. as the tuple outside the bag is also
> contained within. So size has nothing to do with it nor does the IsEmpty...
> I'll just write it as a UDF but would have assumed there was a way to do
> this already, given that it should be a fairly common thing?
>
> Thanks!
> Flo
>
>
>
> On Mon, Feb 13, 2012 at 1:06 PM, Russell Jurney <[email protected]
> >wrote:
>
> > Won't SIZE() count the tuples in a bag, and return 0 if it is empty?
> >
> > On Feb 13, 2012, at 1:02 PM, Dmitriy Ryaboy <[email protected]> wrote:
> >
> > > Flo, how do you want to test for containment -- based on tuple fields?
> > > That doesn't exist afaik (contributions welcome). It'd be fairly
> trivial
> > to
> > > write.
> > >
> > >
> > > On Mon, Feb 13, 2012 at 11:15 AM, Prashant Kommireddi
> > > <[email protected]>wrote:
> > >
> > >> IsEmpty is the function you might be looking for
> > >> http://pig.apache.org/docs/r0.9.1/func.html#isempty
> > >>
> > >> Thanks,
> > >> Prashant
> > >>
> > >> On Mon, Feb 13, 2012 at 9:41 AM, Flo Leibert <
> > [email protected]
> > >>> wrote:
> > >>
> > >>> Hi -
> > >>> Is there a good way to see if a bag contains a tuple? Given a record
> > that
> > >>> has a tuple T and a Bag (a bag could contain 0 to n tuples), how do I
> > >>> filter the records where the bag contains the tuple?
> > >>>
> > >>> I could write a custom UDF but Pig probably has a built-in function
> > that
> > >>> takes care of this? Looked at the list of built-in functions but
> > couldn't
> > >>> identify one - afaict, there's not "CONTAINS" function.
> > >>>
> > >>> Any pointers would be appreciated!
> > >>>
> > >>> Thanks,
> > >>> florian
> > >>>
> > >>
> >
>
