[ https://issues.apache.org/jira/browse/CALCITE-6193 ]
Mou Wu deleted comment on CALCITE-6193:
---------------------------------
was (Author: JIRAUSER290047):
Current test case is already a minimal test case, the traits of this test case
is:
# At least three common sub-expressions in query.
# The first one can be replaced by child-node of mv, but can not be replaced
by the mv itself.
# The second one and the third one can be rewritten by mv, but can not be
replaced by mv completely.
So the third one may be skipped.
> SubstitutionVisitor stop trying incorrect subtree because of wrong parent
> relationship when replace query
> ---------------------------------------------------------------------------------------------------------
>
> Key: CALCITE-6193
> URL: https://issues.apache.org/jira/browse/CALCITE-6193
> Project: Calcite
> Issue Type: Bug
> Reporter: Mou Wu
> Assignee: Mou Wu
> Priority: Major
> Labels: pull-request-available
> Fix For: 1.37.0
>
>
> {code:java}
> @Test void testStopTryIncorrectSubtree() {
> final String mv = ""
> + "select \"empid\", \"deptno\"\n"
> + "from \"emps\"\n"
> + "where \"salary\" > 1000\n"
> + "group by \"empid\", \"deptno\"";
> final String query = ""
> + "select t1.\"deptno\"\n"
> + "from (\n"
> + "select \"deptno\"\n"
> + "from \"emps\"\n"
> + "where \"salary\" > 1000\n"
> + "union all\n"
> + "select \"deptno\"\n"
> + "from \"emps\"\n"
> + "where \"salary\" > 1000\n"
> + "group by \"deptno\"\n"
> + ") as t1 inner join (\n"
> + "select \"deptno\"\n"
> + "from \"emps\"\n"
> + "where \"salary\" > 1000\n"
> + "group by \"deptno\"\n"
> + ") as t2 on t1.\"deptno\" = t2.\"deptno\"\n";
> sql(mv, query)
> .checkingThatResultContains(""
> + "LogicalCalc(expr#0..1=[{inputs}], deptno=[$t0])\n"
> + " LogicalJoin(condition=[=($0, $1)], joinType=[inner])\n"
> + " LogicalUnion(all=[true])\n"
> + " LogicalCalc(expr#0..4=[{inputs}], expr#5=[1000],
> expr#6=[>($t3, $t5)], deptno=[$t1], $condition=[$t6])\n"
> + " LogicalTableScan(table=[[hr, emps]])\n"
> + " LogicalAggregate(group=[{1}])\n"
> + " EnumerableTableScan(table=[[hr, MV0]])\n"
> + " LogicalAggregate(group=[{1}])\n"
> + " EnumerableTableScan(table=[[hr, MV0]])"
> ).ok();
> }{code}
> The test case above will fail because the second mv0 not be matched.
> The root cause is that SubstitutionVisitor replace child nodes withÂ
> targetDescendant node itself, not a deep-copy replica, so they may share the
> same node and the same parent node, thus the incorrect parent relationship
> may occur, it will make stopTrying be wrong.
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