LEFT OUTER JOIN:The Hive LEFT OUTER JOIN returns all the rows from the left table, even if there
are no matches in the right table. This means, if the ON clause matches 0 (zero) records in the
right table, then the JOIN still returns a row in the result, but with NULL in each column from
the right table.
A LEFT JOIN returns all the values from the left table, plus the matched values from the right
table or NULL in case of no matching JOIN predicate.
The syntax ‘FROM a LEFT OUTER join b’ should be written in one line so as to grasp how it
works: a is to the LEFT of b in this query, then all rows from a are kept.
Left
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