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MapReduce >> mail # user >> Doubt on Input and Output Mapper - Key value pairs


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Doubt on Input and Output Mapper - Key value pairs
Hi,

Which of the following is correct w.r.t mapper.

(a) It accepts a single key-value pair as input and can emit any number of
key-value pairs as output, including zero.
(b) It accepts a single key-value pair as input and emits a single key and
list of corresponding values as output
regards,
Rams
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