Taras Bobrovytsky 46c3e43edb IMPALA-3232: Allow not-exists uncorrelated subqueries ...

Before this patch, correlated exists and not exists subqueries were
rewritten as as left semi and anti joins respectively. Uncorrelated
exists subqueries were rewritten as cross joins, and uncorrelated
not-exists subqueries were not supported at all. This patch takes
advantage of the nested loop join that was recently introduced, which
allows us to rewrite both correlated and uncorrelated exists subqueries
as left semi joins and both correlated and uncorrelated not-exists
subqueries as anti joins.

Change-Id: I52ae12f116d026190f3a2a7575cda855317d11e8
Reviewed-on: http://gerrit.cloudera.org:8080/2792
Reviewed-by: Taras Bobrovytsky <tbobrovytsky@cloudera.com>
Tested-by: Internal Jenkins

2016-05-12 23:06:36 -07:00

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