[CALCITE-5670] Assertion error in SemiJoinJoinTransposeRule when Semi-Join has keys from both tables of the bottom Join

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.34.0
• Fix Version/s: 1.35.0
• Labels: pull-request-available
• Assignee: Roman Kondakov
• Reporter: Roman Kondakov
• Created: 23/Apr/23 11:32
• Updated: 27/Jul/23 10:22
• Resolved: 25/Apr/23 11:17

Description

The following test will raise the assertion error:

  @Test void testPushSemiJoinPastJoinRuleNotHappensJoinKeysDifferentOrigin() {
    // tests the case where the semijoin is pushed to the right
    final String sql = "select e.ename from emp e, dept d, bonus b\n"
        + "where e.deptno = d.deptno and e.ename = b.ename and d.name = b.job";
    sql(sql)
        .withRule(CoreRules.FILTER_INTO_JOIN,
            CoreRules.JOIN_ADD_REDUNDANT_SEMI_JOIN,
            CoreRules.SEMI_JOIN_JOIN_TRANSPOSE)
        .check();
  }

java.lang.AssertionError
	at org.apache.calcite.rel.rules.SemiJoinJoinTransposeRule.onMatch(SemiJoinJoinTransposeRule.java:112)
	at org.apache.calcite.plan.AbstractRelOptPlanner.fireRule(AbstractRelOptPlanner.java:337)
	at org.apache.calcite.plan.hep.HepPlanner.applyRule(HepPlanner.java:556)
	at org.apache.calcite.plan.hep.HepPlanner.applyRules(HepPlanner.java:420)
	at org.apache.calcite.plan.hep.HepPlanner.executeRuleInstance(HepPlanner.java:243)
	at org.apache.calcite.plan.hep.HepInstruction$RuleInstance$State.execute(HepInstruction.java:178)
	at org.apache.calcite.plan.hep.HepPlanner.lambda$executeProgram$0(HepPlanner.java:211)
	at com.google.common.collect.ImmutableList.forEach(ImmutableList.java:422)
	at org.apache.calcite.plan.hep.HepPlanner.executeProgram(HepPlanner.java:210)
	at org.apache.calcite.plan.hep.HepProgram$State.execute(HepProgram.java:118)
	at org.apache.calcite.plan.hep.HepPlanner.executeProgram(HepPlanner.java:205)
	at org.apache.calcite.plan.hep.HepPlanner.findBestExp(HepPlanner.java:191)
	at org.apache.calcite.test.RelOptFixture.checkPlanning(RelOptFixture.java:379)
	at org.apache.calcite.test.RelOptFixture.check(RelOptFixture.java:330)
	at org.apache.calcite.test.RelOptFixture.check(RelOptFixture.java:314)
	at org.apache.calcite.test.RelOptRulesTest.testPushSemiJoinPastJoinRuleNotHappensJoinKeysDifferentOrigin(RelOptRulesTest.java:2650)

The problem here is that the case when top-most Semi-Join has join keys from both tables of the bottom Join is considered impossible, though it happens in practice.

Issue Links

• links to: GitHub Pull Request #3172