[jira] [Created] (CALCITE-714) Decorrelation does not push join condition into subquery

["Aman Sinha (JIRA)" <ji...@apache.org>]

Aman Sinha created CALCITE-714:
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             Summary: Decorrelation does not push join condition into subquery
                 Key: CALCITE-714
                 URL: https://issues.apache.org/jira/browse/CALCITE-714
             Project: Calcite
          Issue Type: Bug
    Affects Versions: 1.1.0-incubating
            Reporter: Aman Sinha
            Assignee: Julian Hyde


When decorrelating a scalar aggregate subquery,  we push copies of the tables from the outer query block into the subquery but don't push the join condition, thereby creating a cartesian join.  This seems to be a regression. 

Query: 
{code}
select count(*) 
    from dfs.`/Users/asinha/data/tpch-sf1/nation` n, dfs.`/Users/asinha/data/tpch-sf1/orders` o 
         where n.n_nationkey = o.o_orderkey 
         and n.n_nationkey > (select avg(ps.ps_suppkey) from dfs.`/Users/asinha/data/tpch-sf1/partsupp` ps
                               where n.n_regionkey = ps.ps_partkey);
{code}

Here's the plan on an earlier version of Calcite (I am not sure of the version number but it was before the decorrelation refactoring),  Note the join between nation and orders at the leaf level has a equi-join condition.  
{code} 
AggregateRel(group=[{}], EXPR$0=[COUNT()])
  ProjectRel($f0=[$0])
    ProjectRel($f0=[0])
      FilterRel(condition=[>($1, $5)])
        ProjectRel(*=[$0], n_nationkey=[$1], n_regionkey=[$2], *0=[$3], o_orderkey=[$4], EXPR$0=[$6])
          JoinRel(condition=[=($2, $5)], joinType=[left])
            JoinRel(condition=[=($1, $4)], joinType=[inner])
              EnumerableTableAccessRel(table=[[dfs, /Users/asinha/data/tpch-sf1/nation]])
              EnumerableTableAccessRel(table=[[dfs, /Users/asinha/data/tpch-sf1/orders]])
            AggregateRel(group=[{0}], EXPR$0=[AVG($1)])
              ProjectRel($f0=[$1], ps_suppkey=[$0])
                ProjectRel(ps_suppkey=[$2], $f0=[$3])
                  FilterRel(condition=[=($3, $1)])
                    JoinRel(condition=[true], joinType=[inner])
                      EnumerableTableAccessRel(table=[[dfs, /Users/asinha/data/tpch-sf1/partsupp]])
                      AggregateRel(group=[{0}])
                        ProjectRel($f0=[$2])
                          JoinRel(condition=[=($1, $4)], joinType=[inner])
                            EnumerableTableAccessRel(table=[[dfs, /Users/asinha/data/tpch-sf1/nation]])
                            EnumerableTableAccessRel(table=[[dfs, /Users/asinha/data/tpch-sf1/orders]])
{code}

Here's the new plan (I am on version 1.1.0 but I think the plan has not changed in the latest version).  Note the join between nation and orders at the leaf level does not have any join condition. 
{code}
LogicalAggregate(group=[{}], EXPR$0=[COUNT()])
  LogicalProject($f0=[$0])
    LogicalProject($f0=[0])
      LogicalFilter(condition=[AND(=($1, $4), >($1, $5))])
        LogicalProject(*=[$0], n_nationkey=[$1], n_regionkey=[$2], *0=[$3], o_orderkey=[$4], EXPR$0=[$6])
          LogicalJoin(condition=[=($2, $5)], joinType=[left])
            LogicalJoin(condition=[true], joinType=[inner])
              EnumerableTableScan(table=[[dfs, /Users/asinha/data/tpch-sf1/nation]])
              EnumerableTableScan(table=[[dfs, /Users/asinha/data/tpch-sf1/orders]])
            LogicalAggregate(group=[{0}], EXPR$0=[AVG($1)])
              LogicalProject(n_regionkey=[$1], ps_suppkey=[$0])
                LogicalProject(ps_suppkey=[$2], n_regionkey=[$3])
                  LogicalFilter(condition=[=($3, $1)])
                    LogicalJoin(condition=[true], joinType=[inner])
                      EnumerableTableScan(table=[[dfs, /Users/asinha/data/tpch-sf1/partsupp]])
                      LogicalAggregate(group=[{0}])
                        LogicalProject(n_regionkey=[$2])
                          LogicalJoin(condition=[true], joinType=[inner])
                            EnumerableTableScan(table=[[dfs, /Users/asinha/data/tpch-sf1/nation]])
                            EnumerableTableScan(table=[[dfs, /Users/asinha/data/tpch-sf1/orders]])
{code}



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