[CALCITE-1984] Incorrect rewriting with materialized views using DISTINCT in aggregate functions

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.13.0
• Fix Version/s: 1.15.0
• Component/s: core
• Assignee: Jesús Camacho Rodríguez
• Reporter: fei.chen
• Created: 13/Sep/17 05:58
• Updated: 27/Feb/24 22:23
• Resolved: 09/Nov/17 04:38

Description

I had written a test as follows . It runs to succeed . But , the result seems not right . The “count distinct” aggregation should not be changed to “count”.

@Test public void testAggregateMaterializationOnCountDistinctQuery1() {
    checkMaterialize(
        "select \"deptno\",  \"empid\" ,\"salary\"\n"
            + "from \"emps\" group by \"deptno\",  \"empid\",\"salary\"",
        "select \"deptno\", count( distinct \"empid\")" + "from (select \"deptno\",  \"empid\" \n"
            + "from \"emps\" group by \"deptno\",  \"empid\")  group by \"deptno\"",
        HR_FKUK_MODEL,
        CalciteAssert.checkResultContains(
            "EnumerableAggregate(group=[{0}], S=[COUNT($1)])\n" +
                "  EnumerableTableScan(table=[[hr, m0]]"));
  }