[CALCITE-3087] AggregateOnProjectToAggregateUnifyRule ignores Project incorrectly when its Mapping breaks ordering

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.20.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Feng Zhu
• Reporter: Haisheng Yuan
• Created: 22/May/19 23:59
• Updated: 25/Oct/19 13:09
• Resolved: 11/Jun/19 17:46

Description

Add the following test to MaterializationTest:

@Test public void testAggregateGroupSetsRollUp0() {
    checkMaterialize(
        "select \"empid\", \"deptno\", count(*) as c, sum(\"salary\") as s from \"emps\" "
            + "group by \"empid\", \"deptno\"",
        "select count(*) + 1 as c,  \"deptno\" from \"emps\" group by cube(\"deptno\", \"empid\")",
        HR_FKUK_MODEL,
        CalciteAssert.checkResultContains(
            "EnumerableCalc(expr#0..2=[{inputs}], expr#3=[1], "
                + "expr#4=[+($t2, $t3)], C=[$t4], deptno=[$t1])\n"
                + "  EnumerableAggregate(group=[{0, 1}], groups=[[{0, 1}, {0}, {1}, {}]], agg#0=[$SUM0($2)])\n"
                + "    EnumerableTableScan(table=[[hr, m0]])"));
  }

We got error:

Caused by: java.lang.IllegalArgumentException: must be sorted: [{0, 1}, {1}, {0}, {}]
	at org.apache.calcite.rel.core.Aggregate$Group.induce(Aggregate.java:472)
	at org.apache.calcite.rel.mutable.MutableAggregate.getGroupType(MutableAggregate.java:83)
	at org.apache.calcite.plan.SubstitutionVisitor.unifyAggregates(SubstitutionVisitor.java:1281)
	at org.apache.calcite.plan.SubstitutionVisitor$AggregateOnProjectToAggregateUnifyRule.apply(SubstitutionVisitor.java:1345)
	at org.apache.calcite.plan.SubstitutionVisitor.go(SubstitutionVisitor.java:531)
	at org.apache.calcite.plan.SubstitutionVisitor.go(SubstitutionVisitor.java:466)
	at org.apache.calcite.plan.MaterializedViewSubstitutionVisitor.go(MaterializedViewSubstitutionVisitor.java:56)
	at org.apache.calcite.plan.RelOptMaterializations.substitute(RelOptMaterializations.java:200)
	at org.apache.calcite.plan.RelOptMaterializations.useMaterializedViews(RelOptMaterializations.java:72)
	at org.apache.calcite.plan.volcano.VolcanoPlanner.registerMaterializations(VolcanoPlanner.java:348)
	at org.apache.calcite.plan.volcano.VolcanoPlanner.findBestExp(VolcanoPlanner.java:584)

The reason is that Mappings.apply2 doesn't sort.

Issue Links

• is related to: CALCITE-3448 AggregateOnCalcToAggregateUnifyRule ignores Project incorrectly when there's missing grouping or mapping breaks ordering
• links to: GitHub Pull Request #1252