[
https://issues.apache.org/jira/browse/AVRO-581?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12890636#action_12890636
]
Tom White commented on AVRO-581:
--------------------------------
> The javadoc for setMapOutputSchema says you should only call it if it differs
> from the final output schema and that it must always be a Pair schema. Is
> that not clear enough?
It's clear, but I was going by analogy with Hadoop, where (I think) you can
just call JobConf#setMapOutputKeyClass() and JobConf#setMapOutputValueClass()
for map-only jobs. Could we do a similar thing for the Avro API?
Otherwise, I'm +1 on this.
> java: add reducer that separates keys and values when map output is pairs
> -------------------------------------------------------------------------
>
> Key: AVRO-581
> URL: https://issues.apache.org/jira/browse/AVRO-581
> Project: Avro
> Issue Type: New Feature
> Components: java
> Reporter: Doug Cutting
> Assignee: Doug Cutting
> Fix For: 1.4.0
>
> Attachments: AVRO-581.patch, AVRO-581.patch, AVRO-581.patch,
> AVRO-581.patch, weather-sorted.avro, weather.avro
>
>
> We should add a Pair<K,V> class, implementing SpecificRecord, that combines
> instances of two schemas (specific or generic). Pairs would be compared by
> key, ignoring value. The template for its schema would be:
> {code}
> {"type": "record", "name": "org.apache.avro.mapred.Pair", "fields":[
> {"name": "key", "type":" <<insert key schema here>>},
> {"name": "value", "order": "ignore", "type": <<insert value schema>>}
> ]}
> {code}
> When map outputs are instances of this class, a reducer may be used whose
> reduce method is something like:
> public abstract void reduce(K key, Iterable<V> values);
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
