[FLINK-21592] RemoveSingleAggregateRule fails due to nullability mismatch

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.12.2
• Fix Version/s: 1.13.0
• Component/s: Table SQL / Planner
• Labels: pull-request-available
• Assignee: Rui Li
• Reporter: Rui Li
• Created: 04/Mar/21 06:18
• Updated: 28/May/21 09:06
• Resolved: 14/Apr/21 09:52

Description

The test case to reproduce the issue:

    @Test
    public void test() throws Exception {
        tableEnv.executeSql("create table foo(x int,y int)");
        tableEnv.executeSql("create table bar(i int,s string)");
        System.out.println(tableEnv.explainSql("select (select count(x)-1 from foo where foo.y=bar.i) from bar"));
    }

Error stack trace is:

java.lang.AssertionError: Cannot add expression of different type to set:
set type is RecordType(BIGINT NOT NULL $f0) NOT NULL
expression type is RecordType(BIGINT $f0) NOT NULL
set is rel#94:LogicalAggregate.NONE.any.[](input=HepRelVertex#93,group={},agg#0=SINGLE_VALUE($0))
expression is LogicalProject($f0=[CAST(-($0, 1)):BIGINT])
  LogicalAggregate(group=[{}], agg#0=[COUNT($0)])
    LogicalProject(x=[$0])
      LogicalFilter(condition=[=($1, $cor0.i)])
        LogicalTableScan(table=[[test-catalog, default, foo]])


	at org.apache.calcite.plan.RelOptUtil.verifyTypeEquivalence(RelOptUtil.java:381)
	at org.apache.calcite.plan.hep.HepRuleCall.transformTo(HepRuleCall.java:58)
	at org.apache.calcite.plan.RelOptRuleCall.transformTo(RelOptRuleCall.java:268)
	at org.apache.calcite.plan.RelOptRuleCall.transformTo(RelOptRuleCall.java:283)
	at org.apache.calcite.sql2rel.RelDecorrelator$RemoveSingleAggregateRule.onMatch(RelDecorrelator.java:1881)
	at org.apache.calcite.plan.AbstractRelOptPlanner.fireRule(AbstractRelOptPlanner.java:333)
	at org.apache.calcite.plan.hep.HepPlanner.applyRule(HepPlanner.java:542)
	at org.apache.calcite.plan.hep.HepPlanner.applyRules(HepPlanner.java:407)
	at org.apache.calcite.plan.hep.HepPlanner.executeInstruction(HepPlanner.java:243)
	at org.apache.calcite.plan.hep.HepInstruction$RuleInstance.execute(HepInstruction.java:127)
	at org.apache.calcite.plan.hep.HepPlanner.executeProgram(HepPlanner.java:202)
	at org.apache.calcite.plan.hep.HepPlanner.findBestExp(HepPlanner.java:189)
	at org.apache.calcite.sql2rel.RelDecorrelator.removeCorrelationViaRule(RelDecorrelator.java:346)
	at org.apache.calcite.sql2rel.RelDecorrelator.decorrelateQuery(RelDecorrelator.java:192)
	at org.apache.calcite.sql2rel.RelDecorrelator.decorrelateQuery(RelDecorrelator.java:169)
	at org.apache.flink.table.planner.plan.optimize.program.FlinkDecorrelateProgram.optimize(FlinkDecorrelateProgram.scala:41)

Issue Links

• links to: GitHub Pull Request #15082