Examples with CorrelationId org.apache.beam.vendor.calcite.v1_28_0.org.apache.calcite.rel.core.CorrelationId used on opensource projects

Example 31 with CorrelationId

use of org.apache.beam.vendor.calcite.v1_28_0.org.apache.calcite.rel.core.CorrelationId in project drill by apache.

the class ComplexUnnestVisitor method visit.

public RelNode visit(Uncollect uncollect) {
    RelBuilder builder = DrillRelFactories.LOGICAL_BUILDER.create(uncollect.getCluster(), null);
    RexBuilder rexBuilder = builder.getRexBuilder();
    assert uncollect.getInput() instanceof Project : "Uncollect should have Project input";
    Project project = (Project) uncollect.getInput();
    // If project below uncollect contains only field references, no need to rewrite it
    List<RexNode> projectChildExps = project.getChildExps();
    assert projectChildExps.size() == 1 : "Uncollect does not support multiple expressions";
    RexNode projectExpr = projectChildExps.iterator().next();
    if (projectExpr.getKind() == SqlKind.FIELD_ACCESS) {
        return uncollect;
    }
    // Collects CorrelationId instances used in current rel node
    RelOptUtil.VariableUsedVisitor variableUsedVisitor = new RelOptUtil.VariableUsedVisitor(null);
    project.accept(variableUsedVisitor);
    assert variableUsedVisitor.variables.size() == 1 : "Uncollect supports only single correlated reference";
    CorrelationId oldCorrId = variableUsedVisitor.variables.iterator().next();
    RelNode left = leftInputs.get(oldCorrId);
    // Creates new project to be placed on top of the left input of correlate
    List<RexNode> leftProjExprs = new ArrayList<>();
    List<String> fieldNames = new ArrayList<>();
    for (RelDataTypeField field : left.getRowType().getFieldList()) {
        leftProjExprs.add(rexBuilder.makeInputRef(left, field.getIndex()));
        fieldNames.add(field.getName());
    }
    fieldNames.add(COMPLEX_FIELD_NAME);
    builder.push(left);
    // Adds complex expression with replaced correlation
    // to the projected list from the left
    leftProjExprs.add(new RexFieldAccessReplacer(builder).apply(projectExpr));
    RelNode leftProject = builder.project(leftProjExprs, fieldNames).build();
    leftInputs.put(oldCorrId, leftProject);
    builder.push(project.getInput());
    CorrelationId newCorrId = uncollect.getCluster().createCorrel();
    // stores new CorrelationId to be used during the creation of new Correlate
    updatedCorrelationIds.put(oldCorrId, newCorrId);
    RexNode rexCorrel = rexBuilder.makeCorrel(leftProject.getRowType(), newCorrId);
    // constructs Project below Uncollect with updated RexCorrelVariable
    builder.project(ImmutableList.of(rexBuilder.makeFieldAccess(rexCorrel, leftProjExprs.size() - 1)), ImmutableList.of(COMPLEX_FIELD_NAME));
    return uncollect.copy(uncollect.getTraitSet(), builder.build());
}