Java Code Examples for org.apache.calcite.rel.core.Project#getChildExps()

/** @see #dispatch */
public Result visit(Project e) {
  Result x = visitChild(0, e.getInput());
  parseCorrelTable(e, x);
  if (isStar(e.getChildExps(), e.getInput().getRowType(), e.getRowType())) {
    return x;
  }
  final Builder builder =
      x.builder(e, Clause.SELECT);
  final List<SqlNode> selectList = new ArrayList<>();
  for (RexNode ref : e.getChildExps()) {
    SqlNode sqlExpr = builder.context.toSql(null, ref);
    addSelect(selectList, sqlExpr, e.getRowType());
  }

  builder.setSelect(new SqlNodeList(selectList, POS));
  return builder.result();
}
 

/**
 * @see #dispatch
 */
public Result visit(Project e) {
  Result x = visitChild(0, e.getInput());
  parseCorrelTable(e, x);
  if (isStar(e.getChildExps(), e.getInput().getRowType(), e.getRowType())) {
    return x;
  }
  final Builder builder =
    x.builder(e, Clause.SELECT);
  final List<SqlNode> selectList = new ArrayList<>();
  for (RexNode ref : e.getChildExps()) {
    SqlNode sqlExpr = builder.context.toSql(null,
      simplifyDatetimePlus(ref, e.getCluster().getRexBuilder()));
    addSelect(selectList, sqlExpr, e.getRowType());
  }

  builder.setSelect(new SqlNodeList(selectList, POS));
  return builder.result();
}
 

@Override
public Void visitProject(Project project, List<Void> inputStreams) throws Exception {
  beginStage(project);

  List<RexNode> childExps = project.getChildExps();
  RelDataType inputRowType = project.getInput(0).getRowType();
  int outputCount = project.getRowType().getFieldCount();

  pw.print("Context context = new StreamlineContext(Processor.dataContext);\n");
  pw.print("context.values = _data.toArray();\n");
  pw.print(String.format("Object[] outputValues = new Object[%d];\n", outputCount));

  pw.write(rexCompiler.compileToBlock(childExps, inputRowType).toString());

  pw.print("    ctx.emit(new CorrelatedValues(_data.getCorrelated(), outputValues));\n");
  endStage();
  return null;
}
 

@Override
public void onMatch(RelOptRuleCall call) {
  Project project = call.rel(0);
  TableScan scan = call.rel(1);

  try {
    if (scan.getRowType().getFieldList().isEmpty()) {
      return;
    }

    ProjectPushInfo projectPushInfo = DrillRelOptUtil.getFieldsInformation(scan.getRowType(), project.getProjects());
    if (!canPushProjectIntoScan(scan.getTable(), projectPushInfo)
        || skipScanConversion(projectPushInfo.createNewRowType(project.getCluster().getTypeFactory()), scan)) {
      // project above scan may be removed in ProjectRemoveRule for the case when it is trivial
      return;
    }

    DrillScanRelBase newScan = createScan(scan, projectPushInfo);

    List<RexNode> newProjects = new ArrayList<>();
    for (RexNode n : project.getChildExps()) {
      newProjects.add(n.accept(projectPushInfo.getInputReWriter()));
    }

    DrillProjectRelBase newProject =
        createProject(project, newScan, newProjects);

    if (ProjectRemoveRule.isTrivial(newProject)) {
      call.transformTo(newScan);
    } else {
      call.transformTo(newProject);
    }
  } catch (IOException e) {
    throw new DrillRuntimeException(e);
  }
}
 

private boolean checkComplexOutput(Project project) {
  for (RexNode expr: project.getChildExps()) {
    if (expr instanceof RexCall) {
      if (functionRegistry.isFunctionComplexOutput(((RexCall) expr).getOperator().getName())) {
        return true;
      }
    }
  }
  return false;
}
 

@Override
public boolean matches(RelOptRuleCall call) {
  // this cannot operate on a project that has a flatten in it.
  final Project project = call.rel(0);
  for (RexNode e : project.getChildExps()) {
    if (FlattenVisitors.hasFlatten(e)) {
      return false;
    }
  }
  return true;
}
 

@Override
public void onMatch(RelOptRuleCall call) {
  final Project proj = call.rel(0);
  final ScanCrel scan = call.rel(1);

  ProjectPushInfo columnInfo = PrelUtil.getColumns(scan.getRowType(), proj.getProjects());

  // get TableBase, either wrapped in RelOptTable, or TranslatableTable. TableBase table = scan.getTable().unwrap(TableBase.class);
  if (columnInfo == null || columnInfo.isStarQuery()) {
    return;
  }

  ScanCrel newScan = scan.cloneWithProject(columnInfo.columns);

  List<RexNode> newProjects = Lists.newArrayList();
  for (RexNode n : proj.getChildExps()) {
    newProjects.add(n.accept(columnInfo.getInputRewriter()));
  }

  final RelBuilder relBuilder = relBuilderFactory.create(proj.getCluster(), null);
  relBuilder.push(newScan);
  relBuilder.project(newProjects, proj.getRowType().getFieldNames());
  final RelNode newProj = relBuilder.build();

  if (newProj instanceof Project
      && ProjectRemoveRule.isTrivial((Project) newProj)
      && newScan.getRowType().getFullTypeString().equals(newProj.getRowType().getFullTypeString())) {
      call.transformTo(newScan);
  } else {
    if(newScan.getProjectedColumns().equals(scan.getProjectedColumns())) {
      // no point in doing a pushdown that doesn't change anything.
      return;
    }

    call.transformTo(newProj);
  }
}
 

public static boolean hasFlatten(Project project){
  for(RexNode n : project.getChildExps()){
    if(n.accept(new FlattenFinder())){
      return true;
    }
  }
  return false;
}
 

public Result visitProject(Project e) {
  Result x = visitChild(0, e.getInput());
  if (isStar(e.getChildExps(), e.getInput().getRowType())) {
    return x;
  }
  final Builder builder =
      x.builder(e, Clause.SELECT);
  final List<SqlNode> selectList = new ArrayList<>();
  for (RexNode ref : e.getChildExps()) {
    SqlNode sqlExpr = builder.context.toSql(null, ref);
    addSelect(selectList, sqlExpr, e.getRowType());
  }
  builder.setSelect(new SqlNodeList(selectList, POS));
  return builder.result();
}
 

public void add(Project project){
  for(RexNode e : project.getChildExps()){
    e.accept(this);
  }
}
 

/**
 * Process the Result from visiting a Project node's child.
 *
 * @param project     The project node.
 * @param childResult The Result from calling visit() on the child of project.
 * @return The Result of visiting the Project node itself.
 */
protected DremioRelToSqlConverter.Result processProjectChild(Project project, DremioRelToSqlConverter.Result childResult) {
  // unlike the super impl #visit(Project), this expands star ("*") if additional push downs are enabled

  Pointer<Boolean> isPartial = new Pointer<>(false);
  project.accept(new StatelessRelShuttleImpl() {
    @Override
    public RelNode visit(TableScan scan) {
      if (scan instanceof ScanRelBase) {
        ScanRelBase tableScan = (ScanRelBase) scan;
        if (tableScan.getTableMetadata().getSchema().getFieldCount() != tableScan.getProjectedColumns().size()) {
          isPartial.value = true;
        }
      }
      return scan;
    }
  });

  PlannerSettings plannerSettings = PrelUtil.getPlannerSettings(project.getCluster());
  if (plannerSettings != null &&
    !plannerSettings.getOptions().getOption(PlannerSettings.JDBC_PUSH_DOWN_PLUS) &&
    !isPartial.value &&
    isStar(project.getChildExps(), project.getInput().getRowType(), project.getRowType())) {
    return childResult;
  }

  final DremioRelToSqlConverter.Builder builder =
    childResult.builder(project, SqlImplementor.Clause.SELECT);
  final List<SqlNode> selectList = new ArrayList<>();
  for (RexNode ref : project.getChildExps()) {
    SqlNode sqlExpr = builder.context.toSql(null, simplifyDatetimePlus(ref, project.getCluster().getRexBuilder()));
    if ((getDialect().shouldInjectNumericCastToProject() && isDecimal(ref.getType())) ||
        (getDialect().shouldInjectApproxNumericCastToProject() && isApproximateNumeric(ref.getType()))) {
      if (!((sqlExpr.getKind() == SqlKind.CAST) || (sqlExpr.getKind() == SqlKind.AS && ((SqlBasicCall) sqlExpr).operand(0).getKind() == SqlKind.CAST))) {
        // Add an explicit cast around this projection.
        sqlExpr = SqlStdOperatorTable.CAST.createCall(POS, sqlExpr, getDialect().getCastSpec(ref.getType()));
      }
    }

    addSelect(selectList, sqlExpr, project.getRowType());
  }

  builder.setSelect(new SqlNodeList(selectList, POS));
  return builder.result();
}