THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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All of the above queries could be correlated or uncorrelated.
Design for this will be similar to the work done in HIVE-15456
- genLogicalPlan will go over select list to do the following:
- If subquery is not top level expression throw an error
- Otherwise, generate appropriate plan by using RexSubquery to represent subquery
- HiveSubqueryRemoveRule will then be applied to remove the RexSubquery node and rewrite the query into join.
- HiveRelDecorrelator::decorrelateQuery will then be used to decorrelate correlated queries.