[jira] [Created] (CALCITE-3922) ProjectRemoveRule drops aliases when used with HepPlanner

["Steven Talbot (Jira)" <ji...@apache.org>]

Steven Talbot created CALCITE-3922:
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             Summary: ProjectRemoveRule drops aliases when used with HepPlanner
                 Key: CALCITE-3922
                 URL: https://issues.apache.org/jira/browse/CALCITE-3922
             Project: Calcite
          Issue Type: Bug
            Reporter: Steven Talbot


The line at [https://github.com/apache/calcite/blob/15fa9bc67a8ed12ec6b8e0d1dbced8760ae307ab/core/src/main/java/org/apache/calcite/rel/rules/ProjectRemoveRule.java#L67] checks for the input being an instanceof Project, but in the HepPlanner every input is always a HepRelVertex.

 

I struggled writing a test for this, but I finally got one (in HepPlannerTest). The thing the test does is similar to how I hit this: you tend to only have trivial projects on top of other trivial projects if a rule moved them around. RelBuilder and SqlToRelConverter will just pre-squash them for you.

 
{code:java}
   @Test public void testProjectRemoveRuleWithAliases() {
    HepProgram prog = HepProgram.builder()
        .addRuleInstance(FilterProjectTransposeRule.INSTANCE)
        .addRuleInstance(ProjectRemoveRule.INSTANCE)
        .build();
    HepPlanner planner = new HepPlanner(prog);
    RelBuilder relBuilder = RelBuilder.create(Frameworks.newConfigBuilder().build());
    String[] fieldNames = {"name", "other"};
    relBuilder.values(fieldNames, "something", "something else");
    relBuilder.project(relBuilder.field("name"));
    // add a filter so the projects won't squash together: it will be moved below by the transpose rule
    relBuilder.filter(relBuilder.call(SqlStdOperatorTable.LIKE, relBuilder.field("name"), relBuilder.literal("something")));
    relBuilder.rename(ImmutableList.of("name1"));
    planner.setRoot(relBuilder.build());
    RelNode opt = planner.findBestExp();
    assertEquals(LogicalValues.class, opt.getInput(0).getInput(0).getClass(), "should have removed the project");
    assertEquals("name1", opt.getRowType().getFieldNames().get(0), "should have kept the rename");
  }
{code}
 



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