[CALCITE-6422] Query with '<>' throws NullPointerException during materialized view matching

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.38.0
• Labels: pull-request-available
• Assignee: Mou Wu
• Reporter: Mou Wu
• Created: 27/May/24 08:47
• Updated: 17/Oct/24 22:41
• Resolved: 17/Oct/24 22:41

Description

If a materialized view compares two nullable columns using '=', and a query on that materialized view compares the same column using '<>', SubstitutionVisitor.mayBeSatisfiable causes RexLiteral.booleanValue to throw a NullPointerException.

Add the test case in MaterializedViewRelOptRulesTest to reproduce this bug:

@Test public void testNpeInSplitFilterOfSubstitutionVisitor() {
  sql("select \"col1\", \"col2\""
          + " from \"nullables\""
          + " where \"col1\" <> \"col2\" and \"col3\" = 1",
      "select \"col1\", \"col2\""
          + " from \"nullables\""
          + " where \"col1\" = \"col2\" and \"col3\" = 1")
      .checkingThatResultContains(""
          + "EnumerableCalc(expr#0..2=[{inputs}], expr#3=[=($t0, $t1)], expr#4=[CAST($t2):INTEGER NOT NULL], expr#5=[1], expr#6=[=($t4, $t5)], expr#7=[AND($t3, $t6)], proj#0..1=[{exprs}], $condition=[$t7])\n"
          + "  EnumerableTableScan(table=[[hr, nullables]])")
      .ok();
} 

Notes: col1 and col2 of table nullables should be nullable.

A NullPointerException will be thrown:
 
java.lang.RuntimeException: Error while applying rule MaterializedViewJoinRule(Filter), args rel#65:LogicalFilter.NONE.[](input=RelSubset#64,condition=AND(=($0, $1), =(CAST($2):INTEGER NOT NULL, 1)))
    at org.apache.calcite.plan.volcano.VolcanoRuleCall.onMatch(VolcanoRuleCall.java:250)
    at org.apache.calcite.plan.volcano.IterativeRuleDriver.drive(IterativeRuleDriver.java:59)
    at org.apache.calcite.plan.volcano.VolcanoPlanner.findBestExp(VolcanoPlanner.java:524)
    at org.apache.calcite.tools.Programs.lambda$standard$3(Programs.java:282)
    at org.apache.calcite.tools.Programs$SequenceProgram.run(Programs.java:348)
    at org.apache.calcite.test.MaterializedViewRelOptRulesTest$1.optimize(MaterializedViewRelOptRulesTest.java:51)
    at org.apache.calcite.test.MaterializedViewTester.checkMaterialize(MaterializedViewTester.java:77)
    at org.apache.calcite.test.MaterializedViewFixture.ok(MaterializedViewFixture.java:56)
    at org.apache.calcite.test.MaterializedViewRelOptRulesTest.testNpeInSplitFilterOfSubstitutionVisitor(MaterializedViewRelOptRulesTest.java:1241)
Caused by: java.lang.NullPointerException
    at org.apache.calcite.rex.RexLiteral.booleanValue(RexLiteral.java:1182)
    at org.apache.calcite.plan.SubstitutionVisitor.mayBeSatisfiable(SubstitutionVisitor.java:446)
    at org.apache.calcite.plan.SubstitutionVisitor.splitFilter(SubstitutionVisitor.java:310)
    at org.apache.calcite.rel.rules.materialize.MaterializedViewRule.computeCompensationPredicates(MaterializedViewRule.java:862)
    at org.apache.calcite.rel.rules.materialize.MaterializedViewRule.perform(MaterializedViewRule.java:364)
    at org.apache.calcite.rel.rules.materialize.MaterializedViewOnlyFilterRule.onMatch(MaterializedViewOnlyFilterRule.java:50)
    at org.apache.calcite.plan.volcano.VolcanoRuleCall.onMatch(VolcanoRuleCall.java:223)
    ... 78 more

Issue Links

• links to: GitHub Pull Request #3800