Exemplo n.º 1
0
  /**
   * Determines whether a {@link RexCall} requires decimal expansion. It usually requires expansion
   * if it has decimal operands.
   *
   * <p>Exceptions to this rule are:
   *
   * <ul>
   *   <li>isNull doesn't require expansion
   *   <li>It's okay to cast decimals to and from char types
   *   <li>It's okay to cast nulls as decimals
   *   <li>Casts require expansion if their return type is decimal
   *   <li>Reinterpret casts can handle a decimal operand
   * </ul>
   *
   * @param expr expression possibly in need of expansion
   * @param recurse whether to check nested calls
   * @return whether the expression requires expansion
   */
  public static boolean requiresDecimalExpansion(RexNode expr, boolean recurse) {
    if (!(expr instanceof RexCall)) {
      return false;
    }
    RexCall call = (RexCall) expr;

    boolean localCheck = true;
    switch (call.getKind()) {
      case Reinterpret:
      case IsNull:
        localCheck = false;
        break;
      case Cast:
        RelDataType lhsType = call.getType();
        RelDataType rhsType = call.operands[0].getType();
        if (rhsType.getSqlTypeName() == SqlTypeName.NULL) {
          return false;
        }
        if (SqlTypeUtil.inCharFamily(lhsType) || SqlTypeUtil.inCharFamily(rhsType)) {
          localCheck = false;
        } else if (SqlTypeUtil.isDecimal(lhsType) && (lhsType != rhsType)) {
          return true;
        }
        break;
      default:
        localCheck = call.getOperator().requiresDecimalExpansion();
    }

    if (localCheck) {
      if (SqlTypeUtil.isDecimal(call.getType())) {
        // NOTE jvs 27-Mar-2007: Depending on the type factory, the
        // result of a division may be decimal, even though both inputs
        // are integer.
        return true;
      }
      for (int i = 0; i < call.operands.length; i++) {
        if (SqlTypeUtil.isDecimal(call.operands[i].getType())) {
          return true;
        }
      }
    }
    return (recurse && requiresDecimalExpansion(call.operands, recurse));
  }
 // override RexShuttle
 public RexNode visitCall(final RexCall call) {
   int i = reducibleExps.indexOf(call);
   if (i == -1) {
     return super.visitCall(call);
   }
   RexNode replacement = reducedValues.get(i);
   if (addCasts.get(i) && (replacement.getType() != call.getType())) {
     // Handle change from nullable to NOT NULL by claiming
     // that the result is still nullable, even though
     // we know it isn't.
     //
     // Also, we cannot reduce CAST('abc' AS VARCHAR(4)) to 'abc'.
     // If we make 'abc' of type VARCHAR(4), we may later encounter
     // the same expression in a ProjectRel's digest where it has
     // type VARCHAR(3), and that's wrong.
     replacement = rexBuilder.makeCast(call.getType(), replacement);
   }
   return replacement;
 }
Exemplo n.º 3
0
 /**
  * Replaces the operands of a call. The new operands' types must match the old operands' types.
  */
 public static RexCall replaceOperands(RexCall call, RexNode[] operands) {
   if (call.operands == operands) {
     return call;
   }
   for (int i = 0; i < operands.length; i++) {
     RelDataType oldType = call.operands[i].getType();
     RelDataType newType = operands[i].getType();
     if (!oldType.isNullable() && newType.isNullable()) {
       throw Util.newInternal("invalid nullability");
     }
     assert (oldType.toString().equals(newType.toString()));
   }
   return new RexCall(call.getType(), call.getOperator(), operands);
 }
Exemplo n.º 4
0
 public RexNode visitCall(RexCall call) {
   List<RexNode> normalizedOperands = new ArrayList<RexNode>();
   int diffCount = 0;
   for (RexNode operand : call.getOperands()) {
     operand.accept(this);
     final RexNode normalizedOperand = lookup(operand);
     normalizedOperands.add(normalizedOperand);
     if (normalizedOperand != operand) {
       ++diffCount;
     }
   }
   if (diffCount > 0) {
     call = call.clone(call.getType(), normalizedOperands);
   }
   return register(call);
 }
    private void reduceCasts(RexCall outerCast) {
      RexNode[] operands = outerCast.getOperands();
      if (operands.length != 1) {
        return;
      }
      RelDataType outerCastType = outerCast.getType();
      RelDataType operandType = operands[0].getType();
      if (operandType.equals(outerCastType)) {
        removableCasts.add(outerCast);
        return;
      }

      // See if the reduction
      // CAST((CAST x AS type) AS type NOT NULL)
      // -> CAST(x AS type NOT NULL)
      // applies.  TODO jvs 15-Dec-2008:  consider
      // similar cases for precision changes.
      if (!(operands[0] instanceof RexCall)) {
        return;
      }
      RexCall innerCast = (RexCall) operands[0];
      if (innerCast.getOperator() != SqlStdOperatorTable.castFunc) {
        return;
      }
      if (innerCast.getOperands().length != 1) {
        return;
      }
      RelDataTypeFactory typeFactory = preparingStmt.getFarragoTypeFactory();
      RelDataType outerTypeNullable = typeFactory.createTypeWithNullability(outerCastType, true);
      RelDataType innerTypeNullable = typeFactory.createTypeWithNullability(operandType, true);
      if (outerTypeNullable != innerTypeNullable) {
        return;
      }
      if (operandType.isNullable()) {
        removableCasts.add(innerCast);
      }
    }