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From Jinal Shah <jinalshah2...@gmail.com>
Subject Re: Generic class for converting PCollection to PTable
Date Thu, 20 Feb 2014 10:59:03 GMT
Somewhat like that as we are also using that same approach but I was more
thinking of it as
PTables.asPTable(PCollection<V>, Keyfinder<V>, PType<K>) and return as
PTable<K,V>

Basically
KeyFinder<V> is an interface which will have somekind of method like
findKey(V) returning K from that V or calculated or anyway it wants.

Because the only thing that MapFn will be emitting will be Pair<K,V> right.

This is provided V does not change to V1.




On Thu, Feb 20, 2014 at 12:07 AM, Gabriel Reid <gabriel.reid@gmail.com>wrote:

>
>
> > On 20 Feb 2014, at 05:11, Jinal Shah <jinalshah2007@gmail.com> wrote:
> >
> > I didn't knew that, but I was more talking about something like this
> > PCollection<V> to  PTable<K,V> basically.
> >
>
> I think what you want is the PCollection#by method. It takes a MapFn that
> maps each value V to a key, and returns a PTable<K,V>
>
> - Gabriel
>
> >
> >
> >> On Wed, Feb 19, 2014 at 5:49 PM, Josh Wills <jwills@cloudera.com>
> wrote:
> >>
> >> org.apache.crunch.lib.PTables.asPTable is likely what you want.
> >>
> >>
> >> On Wed, Feb 19, 2014 at 3:47 PM, Jinal Shah <jinalshah2007@gmail.com>
> >> wrote:
> >>
> >>> Hi everyone,
> >>>
> >>> Is there a generic way of converting PCollection to PTable? If not, Can
> >> we
> >>> create a generic class? Because we are having lot of places where we
> want
> >>> to perform a join on 2 PCollections so we have to convert it into
> PTables
> >>> and then do a join and then convert it into a PCollection. So i was
> >>> wondering is there a better way of doing this.
> >>>
> >>> Thanks
> >>
> >>
> >>
> >> --
> >> Director of Data Science
> >> Cloudera <http://www.cloudera.com>
> >> Twitter: @josh_wills <http://twitter.com/josh_wills>
> >>
>

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