[CALCITE-2912] MaterializedViewAggregateRule.pushFilterToOriginalViewPlan fails to use valid materialization given query with certain kinds of constant filters

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Assignee: Unassigned
• Reporter: Steven Talbot
• Created: 11/Mar/19 19:25
• Updated: 28/Feb/24 06:03

Description

This seems to stem from 

https://github.com/apache/calcite/blob/d6fb6abd9a17b81a5d8d592860ecd5c2f20ce9b1/core/src/main/java/org/apache/calcite/rel/rules/AbstractMaterializedViewRule.java#L1735

.addRuleInstance(this.aggregateProjectPullUpConstantsRule)

If commented out, the bug does not occur. Also, when that line is commented out, all tests in `MaterializationTest.java` pass. The following test demonstrates the issue (fails on master, passes with line commented out):

@Test public void testAggregateMaterializationWithConstantFilter() {
  checkMaterialize(
          "select \"deptno\", \"name\", count(*) as c\n"
                  + "from \"depts\" group by \"name\", \"deptno\"",
          "select \"name\", count(*) as c\n"
                  + "from \"depts\" where \"name\" = 'a_name' group by \"name\"");
}

From my understanding, the materialization fails to be used because `aggregateProjectPullUpConstantsRule` rewrites the Aggregate in `topNode` at https://github.com/apache/calcite/blob/d6fb6abd9a17b81a5d8d592860ecd5c2f20ce9b1/core/src/main/java/org/apache/calcite/rel/rules/AbstractMaterializedViewRule.java#L1743 to not include the known constant "name" in its group set, rather groups on just deptno and then projects `'a_name'` as a constant. This make that aggregate no longer a superset of the query aggregate and `rewriteView` then fails to properly match the aggregates.

Issue Links

• is related to: CALCITE-1048 Make metadata more robust