Home | About | Sematext search-lucene.com search-hadoop.com
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB
 Search Hadoop and all its subprojects:

Switch to Threaded View
Hive >> mail # user >> Re: getStructFieldData method on StructObjectInspector


Copy link to this message
-
Re: getStructFieldData method on StructObjectInspector
Thanks Edward for your reply on this.

Would you mind giving a very small example on how a struct corresponds to a
Map? I am having hard time understanding what the K/V pairs in the map
would look like.

Thanks again.

On Tue, May 29, 2012 at 10:16 AM, Edward Capriolo <[EMAIL PROTECTED]>wrote:

> Returning custom writables will not work. In most cases the methods
> return Object because the types can be many things that do not fall
> under a single superclass other then object. like Integer,IntWritable,
> Array<IntWritable>, or Map. In your case, a struct corresponds to a
> Map.
>
> On Tue, May 29, 2012 at 11:08 AM, [EMAIL PROTECTED]
> <[EMAIL PROTECTED]> wrote:
> > If someone can help understand this, I would really appreciate.
> >
> > On Fri, May 25, 2012 at 3:58 PM, [EMAIL PROTECTED]
> > <[EMAIL PROTECTED]> wrote:
> >>
> >> I am trying to write a custom ObjectInspector extending the
> >> StructObjectInspector and got a little confused about the use of the
> >> getStructFieldData method on the inspector. Looking at the definition
> of the
> >> method:
> >>
> >> public Object getStructFieldData(Object data, StructField fieldRef);
> >>
> >> I understand that the use of this method is to retrieve the specific
> given
> >> field from the buffer. However, what I don't understand is what is it
> >> expected to return. I looked around the tests and related code and
> mostly
> >> stuff returned was either a LazyPrimitive or a LazyNonPrimitive, but I
> >> couldn't find anything that enforces this(specially given that the
> return
> >> type is a plain "Object")! Does this mean that I am free to return even
> my
> >> custom object as a return type of this method? If so, what is the
> guarantee
> >> that it will be interpreted correctly down the pipeline?
> >>
> >> Thanks,
> >> --
> >> Swarnim
> >
> >
> >
> >
> > --
> > Swarnim
>

--
Swarnim
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB