Partitioning ! how dose the hadoop make it? Use a hash function ? what is
the default function?
Partitioning is the process of determining which reducer instance will
receive which intermediate keys and values. Each mapper must determine for
all of its output (key, value) pairs which reducer will receive them. It
is necessary that for any key, regardless of which mapper instance
generated it, the destination partition is the same Problem: how dose the
hadoop make it? Use a hash function ? what is the function?
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