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Avro >> mail # user >> Grouping comparators - old vs new mapreduce APIs


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Dave Beech 2012-12-11, 15:11
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Doug Cutting 2012-12-11, 17:55
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Re: Grouping comparators - old vs new mapreduce APIs
Thanks Doug. Yes, extra documentation would be good but I think the
subclass would be really useful too. I'll file a JIRA and work on a patch
for it.

Cheers,
Dave
On 11 December 2012 17:55, Doug Cutting <[EMAIL PROTECTED]> wrote:

> On Tue, Dec 11, 2012 at 7:11 AM, Dave Beech <[EMAIL PROTECTED]> wrote:
> > What this means is, if you want to use a grouping comparator with the
> "new"
> > mapreduce API and Avro, you absolutely must provide an implementation of
> > RawComparator, or do the deserialization and delegating method call to
> > compare(x,y) yourself. This really isn't obvious and I haven't found it
> to
> > be documented anywhere.
>
> Sounds like we should at least add some documentation and probably
> also make this simpler.  Perhaps we could provide a subclass of
> AvroKeyComparator that does the deserialization and delegates to
> compare(x,y)?  Then folks can subclass this and override compare(x,y)?
>
> Doug
>