Stamatis Zampetakis created HIVE-24999:
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Summary: HiveSubQueryRemoveRule generates invalid plan for IN
subquery with multiple correlations
Key: HIVE-24999
URL: https://issues.apache.org/jira/browse/HIVE-24999
Project: Hive
Issue Type: Bug
Components: CBO
Reporter: Stamatis Zampetakis
Assignee: Stamatis Zampetakis
The problem can be reproduced by using the following query which at the moment
can be found in {{subquery_in.q}} file:
{code:sql}
explain cbo select * from part where p_name IN (select p_name from part p where
p.p_size = part.p_size AND part.p_size + 121150 = p.p_partkey );
{code}
The plans before and after {{HiveSubQueryRemoveRule}} are shown below:
{noformat}
2021-04-09T14:29:08,031 DEBUG [9f8b0342-5609-4917-95a9-e7abc884f619 main]
parse.CalcitePlanner: Plan before removing subquery:
HiveProject(p_partkey=[$0], p_name=[$1], p_mfgr=[$2], p_brand=[$3],
p_type=[$4], p_size=[$5], p_container=[$6], p_retailprice=[$7], p_comment=[$8])
HiveFilter(condition=[IN($1, {
HiveProject(p_name=[$1])
HiveFilter(condition=[AND(=($5, $cor0.p_size), =(+($cor0.p_size, 121150),
$0))])
HiveTableScan(table=[[default, part]], table:alias=[p])
})])
HiveTableScan(table=[[default, part]], table:alias=[part])
2021-04-09T14:29:08,056 DEBUG [9f8b0342-5609-4917-95a9-e7abc884f619 main]
parse.CalcitePlanner: Plan just after removing subquery:
HiveProject(p_partkey=[$0], p_name=[$1], p_mfgr=[$2], p_brand=[$3],
p_type=[$4], p_size=[$5], p_container=[$6], p_retailprice=[$7], p_comment=[$8])
HiveFilter(condition=[=($1, $12)])
LogicalCorrelate(correlation=[$cor0], joinType=[semi],
requiredColumns=[{5}])
HiveTableScan(table=[[default, part]], table:alias=[part])
HiveProject(p_name=[$1])
HiveFilter(condition=[AND(=($5, $cor0.p_size), =(+($cor0.p_size,
121150), $0))])
HiveTableScan(table=[[default, part]], table:alias=[p])
{noformat}
The plan after applying the rule is invalid. The {{HiveFilter(condition=[=($1,
$12)])}} above the correlate references columns ($12) from the right input
which do not exist since the correlate is of type SEMI. Running the test with
{{-Dcalcite.debug}} property enabled raises an {{AssertionError}} when building
the {{HiveFilter}}.
The problem is hidden at the moment since there is a specific hack in
{{HiveRelDecorrelator}} that turns this invalid plan into a valid one. This
mechanism is very brittle and it can break easily as it happened while fixing
HIVE-24957.
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