Exemple #1
0
 /**
  * Generates a cast for a row type.
  *
  * @param rexBuilder RexBuilder to use for constructing casts
  * @param lhsRowType target row type
  * @param rhsExps expressions to be cast
  * @return cast expressions
  */
 public static RexNode[] generateCastExpressions(
     RexBuilder rexBuilder, RelDataType lhsRowType, RexNode[] rhsExps) {
   RelDataTypeField[] lhsFields = lhsRowType.getFields();
   final int fieldCount = lhsFields.length;
   RexNode[] castExps = new RexNode[fieldCount];
   assert fieldCount == rhsExps.length;
   for (int i = 0; i < fieldCount; ++i) {
     RelDataTypeField lhsField = lhsFields[i];
     RelDataType lhsType = lhsField.getType();
     RelDataType rhsType = rhsExps[i].getType();
     if (lhsType.equals(rhsType)) {
       castExps[i] = rhsExps[i];
     } else {
       castExps[i] = rexBuilder.makeCast(lhsType, rhsExps[i]);
     }
   }
   return castExps;
 }
  private static List<RelCollation> deduceMonotonicity(Prepare.PreparingTable table) {
    final List<RelCollation> collationList = new ArrayList<RelCollation>();

    // Deduce which fields the table is sorted on.
    int i = -1;
    for (RelDataTypeField field : table.getRowType().getFieldList()) {
      ++i;
      final SqlMonotonicity monotonicity = table.getMonotonicity(field.getName());
      if (monotonicity != SqlMonotonicity.NotMonotonic) {
        final RelFieldCollation.Direction direction =
            monotonicity.isDecreasing()
                ? RelFieldCollation.Direction.Descending
                : RelFieldCollation.Direction.Ascending;
        collationList.add(
            RelCollationImpl.of(
                new RelFieldCollation(i, direction, RelFieldCollation.NullDirection.UNSPECIFIED)));
      }
    }
    return collationList;
  }
Exemple #3
0
    private List<RelCollation> deduceMonotonicity(SqlValidatorTable table) {
      final RelDataType rowType = table.getRowType();
      final List<RelCollation> collationList = new ArrayList<RelCollation>();

      // Deduce which fields the table is sorted on.
      int i = -1;
      for (RelDataTypeField field : rowType.getFieldList()) {
        ++i;
        final SqlMonotonicity monotonicity = table.getMonotonicity(field.getName());
        if (monotonicity != SqlMonotonicity.NOT_MONOTONIC) {
          final RelFieldCollation.Direction direction =
              monotonicity.isDecreasing()
                  ? RelFieldCollation.Direction.DESCENDING
                  : RelFieldCollation.Direction.ASCENDING;
          collationList.add(
              RelCollationImpl.of(
                  new RelFieldCollation(
                      i, direction, RelFieldCollation.NullDirection.UNSPECIFIED)));
        }
      }
      return collationList;
    }
Exemple #4
0
 /**
  * Trims a child relational expression, then adds back a dummy project to restore the fields that
  * were removed.
  *
  * <p>Sounds pointless? It causes unused fields to be removed further down the tree (towards the
  * leaves), but it ensure that the consuming relational expression continues to see the same
  * fields.
  *
  * @param rel Relational expression
  * @param input Input relational expression, whose fields to trim
  * @param fieldsUsed Bitmap of fields needed by the consumer
  * @return New relational expression and its field mapping
  */
 protected TrimResult trimChildRestore(
     RelNode rel, RelNode input, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
   TrimResult trimResult = trimChild(rel, input, fieldsUsed, extraFields);
   if (trimResult.right.isIdentity()) {
     return trimResult;
   }
   final RelDataType rowType = input.getRowType();
   List<RelDataTypeField> fieldList = rowType.getFieldList();
   final List<RexNode> exprList = new ArrayList<RexNode>();
   final List<String> nameList = rowType.getFieldNames();
   RexBuilder rexBuilder = rel.getCluster().getRexBuilder();
   assert trimResult.right.getSourceCount() == fieldList.size();
   for (int i = 0; i < fieldList.size(); i++) {
     int source = trimResult.right.getTargetOpt(i);
     RelDataTypeField field = fieldList.get(i);
     exprList.add(
         source < 0
             ? rexBuilder.makeZeroLiteral(field.getType())
             : rexBuilder.makeInputRef(field.getType(), source));
   }
   RelNode project = CalcRel.createProject(trimResult.left, exprList, nameList);
   return new TrimResult(project, Mappings.createIdentity(fieldList.size()));
 }