LEFT, RIGHT, and FULL OUTER JOINs are supported, as are LEFT SEMI JOINs and CROSS JOINs using the equal comparison operator, as shown in the following examples:
SELECT a.* FROM a JOIN b ON (a.id = b.id AND a.department = b.department)
SELECT a.val, b.val, c.val FROM a JOIN b ON (a.key = b.key1) JOIN c ON (c.key = b.key2)
SELECT a.val, b.val FROM a LEFT OUTER JOIN b ON (a.key=b.key) WHERE a.ds='2009-07-07' AND b.ds='2009-07-07'
However, the following syntax fails because of the use of non-equal comparison operators.
SELECT a.* FROM a JOIN b ON (a.id <> b.id)
Impala SQL does not support join syntax in the form of a comma-separated list of tables. The driver, however, overcomes this limitation by translating the SQL into Impala SQL, as shown in the following examples.
