I am trying to understand the working of REDUCE operator in hive.  As
mentioned in one of the docs "both MAP and REDUCE are "syntactic
sugar" for the more general select transform" does it mean REDUCE
applies only on the local batch-data ( acting only as "local-reduce"
) or they do act on the entire values for a particular key ? For MAP
command its ok, as its ok for them to act only on a subset of the
data. But for REDUCE semantics to work it has to act on the entire set
of values for that particular key.

Let me know if I have misunderstood any of the semantics.


Search Discussions

Related Discussions

Discussion Navigation
viewthread | post
Discussion Overview
groupuser @
categorieshive, hadoop
postedFeb 21, '10 at 3:58a
activeFeb 21, '10 at 3:58a

1 user in discussion

Prasenjit mukherjee: 1 post



site design / logo © 2021 Grokbase