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https://issues.apache.org/jira/browse/CALCITE-5166?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17540890#comment-17540890
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Roman Kondakov commented on CALCITE-5166:
-----------------------------------------
Right now, as I can see, there are several logical operators that have no
overloaded methods in {{{}RelShuttle{}}}.
* LogicalWindow
* LogicalTableSpool
* LogicalTableFunctionScan
* LogicalSortExchange
* LogicalSnapshot
* LogicalRepeatUnion
There was a [discussion|https://issues.apache.org/jira/browse/CALCITE-4386]
about whether we need to add new nodes to {{{}RelShuttle{}}}, but there is no
conclusion there.
My personal opinion is that usually, people create their own extensions of
{{RelShuttle}} for use in downstream projects. And that's why we don't need to
add all Logical nodes to {{RelShuttle}} until they are needed for internal
Calcite usage. But it's not a strong opinion. Maybe we need to add support for
{{LogicalWindow}} since it seems a more widely used operator than others.
> Method accept(RelShuttle) is not overridden in LogicalCalc and
> LogicalTableModify
> ---------------------------------------------------------------------------------
>
> Key: CALCITE-5166
> URL: https://issues.apache.org/jira/browse/CALCITE-5166
> Project: Calcite
> Issue Type: Bug
> Components: core
> Affects Versions: 1.30.0
> Reporter: Roman Kondakov
> Assignee: Roman Kondakov
> Priority: Major
> Labels: pull-request-available, pull_request_available
> Fix For: 1.31.0
>
> Time Spent: 20m
> Remaining Estimate: 0h
>
> Method {{RelNode#accept(RelShuttle)}} is not overridden for {{LogicalCalc}}
> and {{{}LogicalTableModify{}}}. This leads to the bug when logic implemented
> in {{RelShuttle#visit(LogicalCalc)}} is never applied because {{visit()}}
> method is never called due to incorrect dispatching.
> This test will fail without {{accept(RelShuttle)}} method is overridden in
> Calc:
> {code:java}
> @Test void testRelShuttleForLogicalCalc() {
> final String sql = "select ename from emp";
> final RelNode rel = sql(sql).toRel();
> final HepProgramBuilder programBuilder = HepProgram.builder();
> programBuilder.addRuleInstance(CoreRules.PROJECT_TO_CALC);
> final HepPlanner planner = new HepPlanner(programBuilder.build());
> planner.setRoot(rel);
> final RelNode calc = planner.findBestExp();
> final List<RelNode> rels = new ArrayList<>();
> final RelShuttleImpl visitor = new RelShuttleImpl() {
> @Override public RelNode visit(LogicalCalc calc) {
> RelNode visitedRel = super.visit(calc);
> rels.add(visitedRel);
> return visitedRel;
> }
> };
> calc.accept(visitor);
> assertThat(rels.size(), is(1));
> assertThat(rels.get(0), isA(LogicalCalc.class));
> } {code}
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