NdbQueryBuilderImpl.hpp

/*
   Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
*/


#ifndef NdbQueryBuilderImpl_H
#define NdbQueryBuilderImpl_H

/* Query-related error codes. */
#define QRY_REQ_ARG_IS_NULL 4800
#define QRY_TOO_FEW_KEY_VALUES 4801
#define QRY_TOO_MANY_KEY_VALUES 4802
#define QRY_OPERAND_HAS_WRONG_TYPE 4803
#define QRY_CHAR_OPERAND_TRUNCATED 4804
#define QRY_NUM_OPERAND_RANGE 4805
#define QRY_MULTIPLE_PARENTS 4806
#define QRY_UNKONWN_PARENT 4807
#define QRY_UNKNOWN_COLUMN 4808
#define QRY_UNRELATED_INDEX 4809
#define QRY_WRONG_INDEX_TYPE 4810
#define QRY_OPERAND_ALREADY_BOUND 4811
#define QRY_DEFINITION_TOO_LARGE 4812
#define QRY_SEQUENTIAL_SCAN_SORTED 4813
#define QRY_RESULT_ROW_ALREADY_DEFINED 4814
#define QRY_HAS_ZERO_OPERATIONS 4815
#define QRY_IN_ERROR_STATE 4816
#define QRY_ILLEGAL_STATE 4817
#define QRY_WRONG_OPERATION_TYPE 4820
#define QRY_SCAN_ORDER_ALREADY_SET 4821
#define QRY_PARAMETER_HAS_WRONG_TYPE 4822
#define QRY_CHAR_PARAMETER_TRUNCATED 4823
#define QRY_MULTIPLE_SCAN_SORTED 4824
#define QRY_BATCH_SIZE_TOO_SMALL 4825

#ifdef __cplusplus
#include <Vector.hpp>
#include <Bitmask.hpp>
#include "NdbQueryBuilder.hpp"
#include "NdbIndexScanOperation.hpp"
#include "ndb_limits.h"

// Forward declared
class NdbTableImpl;
class NdbIndexImpl;
class NdbColumnImpl;
class NdbQueryBuilderImpl;
class NdbQueryDefImpl;
class NdbQueryOperationDefImpl;
class NdbQueryParamValue;
class NdbParamOperandImpl;
class NdbConstOperandImpl;
class NdbLinkedOperandImpl;

// For debuggging.
//#define TRACE_SERIALIZATION

class Uint32Buffer{
public:

//#define TEST_Uint32Buffer

#if defined(TEST_Uint32Buffer)
  STATIC_CONST(initSize = 1);  // Small size to force test of buffer expand.
#else
  STATIC_CONST(initSize = 32); // Initial buffer size, extend on demand but probably sufficent
#endif

  explicit Uint32Buffer():
    m_array(m_local),
    m_avail(initSize),
    m_size(0),
    m_memoryExhausted(false),
    m_bytesLeft(0)
  {}

  ~Uint32Buffer() {
    if (unlikely(m_array != m_local)) {
      delete[] m_array;
    }
  }

  void releaseExtend() {
    if (unlikely(m_array != m_local)) {
      delete[] m_array;
    }
    m_array = NULL;
    m_size = 0;
  }

  Uint32* alloc(Uint32 count) {
    Uint32 reqSize = m_size+count;
    if(unlikely(reqSize >= m_avail)) {
      if (unlikely(m_memoryExhausted)) {
        return NULL;
      }
#if defined(TEST_Uint32Buffer)
      Uint32 newSize = reqSize; // -> Always expand on next alloc
#else
      Uint32 newSize = reqSize*2;
#endif
//    ndbout << "Uint32Buffer::alloc() Extend buffer from: " << m_avail
//           << ", to: " << newSize << endl;
      Uint32* newBuf = new Uint32[newSize];
      if (likely(newBuf!=NULL)) {
        assert(newBuf);
        memcpy (newBuf, m_array, m_size*sizeof(Uint32));
        if (m_array != m_local) {
          delete[] m_array;
        }
        m_array = newBuf;
        m_avail = static_cast<Uint32>(newSize);
      } else {
        m_size = m_avail;
        m_memoryExhausted = true;
        return NULL;
      }
    }
    Uint32* extend = &m_array[m_size];
    m_size += static_cast<Uint32>(count);
    return extend;
  }

  void put(Uint32 idx, Uint32 value) {
    assert(idx < m_size);
    m_array[idx] = value;
  }

  void append(const Uint32 src) {
    m_bytesLeft = 0;
    if (likely(m_size < m_avail)) {
      m_array[m_size++] = src;
    } else {
      Uint32* dst = alloc(1);
      if (likely(dst!=NULL))
        *dst = src;
    }
  }

  void append(const Uint32Buffer& src) {
    assert (!src.isMemoryExhausted());
    m_bytesLeft = 0;
    Uint32 len = src.getSize();
    if (likely(len > 0)) {
      Uint32* dst = alloc(len);
      if (likely(dst!=NULL)) {
        memcpy(dst, src.addr(), len*sizeof(Uint32));
      }
    }
  }

  void appendBytes(const void* src, Uint32 len) {
    if (likely(len > 0)) {
      Uint32 wordCount = 
        static_cast<Uint32>((len + sizeof(Uint32)-1 - m_bytesLeft) 
                            / sizeof(Uint32));
      Uint32* dst = alloc(wordCount);
      if (likely(dst!=NULL)) {
        // Copy src 
        Uint8* const start = reinterpret_cast<Uint8*>(dst) - m_bytesLeft;
        memcpy(start, src, len);
        m_bytesLeft = (m_bytesLeft - len) % sizeof(Uint32);
        // Make sure that any trailing bytes in the last word are zero.
        bzero(start + len, m_bytesLeft);
      }
    }
  }

  void skipRestOfWord()
  { m_bytesLeft = 0; }

  Uint32* addr(Uint32 idx=0) {
    return (likely(!m_memoryExhausted && m_size>idx)) ?&m_array[idx] :NULL;
  }
  const Uint32* addr(Uint32 idx=0) const {
    return (likely(!m_memoryExhausted && m_size>idx)) ?&m_array[idx] :NULL;
  }

  Uint32 get(Uint32 idx) const {
    assert(idx < m_size);
    return m_array[idx];
  }

  bool isMemoryExhausted() const {
    return m_memoryExhausted;
  }

  Uint32 getSize() const {
    return m_size;
  }

private:
  Uint32Buffer(Uint32Buffer&);
  Uint32Buffer& operator=(Uint32Buffer&);

private:
  Uint32  m_local[initSize]; // Initial static bufferspace
  Uint32* m_array;           // Refers m_local initially, or extended large buffer
  Uint32  m_avail;           // Available buffer space
  Uint32  m_size;            // Actuall size <= m_avail
  bool m_memoryExhausted;
  Uint32 m_bytesLeft;
};


class NdbQueryOptionsImpl
{
  friend class NdbQueryOptions;
  friend class NdbQueryOperationDefImpl;

public:
  explicit NdbQueryOptionsImpl()
  : m_matchType(NdbQueryOptions::MatchAll),
    m_scanOrder(NdbQueryOptions::ScanOrdering_void),
    m_parent(NULL),
    m_interpretedCode(NULL)
  {};
  NdbQueryOptionsImpl(const NdbQueryOptionsImpl&);
  ~NdbQueryOptionsImpl();

private:
  NdbQueryOptions::MatchType     m_matchType;
  NdbQueryOptions::ScanOrdering  m_scanOrder;
  NdbQueryOperationDefImpl*      m_parent;
  const NdbInterpretedCode*      m_interpretedCode;

  int copyInterpretedCode(const NdbInterpretedCode& src);

  NdbQueryOptionsImpl&operator=(const NdbQueryOptionsImpl&);  // Not impl.
};


// Implementation of NdbQueryOperation interface

class NdbQueryOperationDefImpl
{
  friend class NdbQueryOperationDef;
  friend class NdbQueryOperationImpl;
  friend class NdbQueryImpl;

public:

  struct IndexBound {     // Limiting 'bound ' definition for indexScan
    NdbQueryOperandImpl* low[MAX_ATTRIBUTES_IN_INDEX];
    NdbQueryOperandImpl* high[MAX_ATTRIBUTES_IN_INDEX];
    Uint32 lowKeys, highKeys;
    bool lowIncl, highIncl;
  };

  /* Currently only a single parent is supported */
  Uint32 getNoOfParentOperations() const
  { return (m_parent) ? 1 : 0; }

  NdbQueryOperationDefImpl& getParentOperation(Uint32 i) const
  { assert(i==0 && m_parent!=NULL);
    return *m_parent;
  }

  NdbQueryOperationDefImpl* getParentOperation() const
  { return m_parent;
  }

  Uint32 getNoOfChildOperations() const
  { return m_children.size(); }

  NdbQueryOperationDefImpl& getChildOperation(Uint32 i) const
  { return *m_children[i]; }

  const NdbTableImpl& getTable() const
  { return m_table; }

  const char* getName() const
  { return m_ident; }

  enum NdbQueryOptions::MatchType getMatchType() const
  { return m_options.m_matchType; }

  enum NdbQueryOptions::ScanOrdering getOrdering() const
  { return m_options.m_scanOrder; }

  const NdbInterpretedCode* getInterpretedCode() const
  { return m_options.m_interpretedCode; }

  Uint32 assignQueryOperationId(Uint32& nodeId)
  { if (getType()==NdbQueryOperationDef::UniqueIndexAccess) nodeId++;
    m_id = nodeId++;
    return m_id;
  }

  // Establish a linked parent <-> child relationship with this operation
  int linkWithParent(NdbQueryOperationDefImpl* parentOp);

  Uint32 addColumnRef(const NdbColumnImpl* column, int& error);

  int addParamRef(const NdbParamOperandImpl* param);

  Uint32 getNoOfParameters() const
  { return m_params.size(); }

  const NdbParamOperandImpl& getParameter(Uint32 ix) const
  { return *m_params[ix]; }

  virtual const NdbIndexImpl* getIndex() const
  { return NULL; }

  virtual const NdbQueryOperandImpl* const* getKeyOperands() const
  { return NULL; } 

  virtual const IndexBound* getBounds() const
  { return NULL; } 

  // Return 'true' is query type is a multi-row scan
  virtual bool isScanOperation() const = 0;

  virtual const NdbQueryOperationDef& getInterface() const = 0; 

  virtual int serializeOperation(Uint32Buffer& serializedTree) = 0;

  const Vector<const NdbColumnImpl*>& getSPJProjection() const {
    return m_spjProjection;
  }

  virtual int checkPrunable(const Uint32Buffer& keyInfo,
                            Uint32  shortestBound,
                            bool&   isPruned,
                            Uint32& hashValue) const {
    isPruned = false;
    return 0;
  }

  virtual ~NdbQueryOperationDefImpl();

protected:
  explicit NdbQueryOperationDefImpl (const NdbTableImpl& table,
                                     const NdbQueryOptionsImpl& options,
                                     const char* ident,
                                     Uint32 ix,
                                     int& error);
public:
  // Get the ordinal position of this operation within the query def.
  Uint32 getQueryOperationIx() const
  { return m_ix; }

  // Get id of node as known inside queryTree
  Uint32 getQueryOperationId() const
  { return m_id; }

  // Get type of query operation
  virtual NdbQueryOperationDef::Type getType() const = 0;

  void printTree(
           Uint32 depth, 
           Bitmask<(NDB_SPJ_MAX_TREE_NODES+31)/32> hasMoreSiblingsMask) const;

protected:
  // QueryTree building:
  // Append list of parent nodes to serialized code
  Uint32 appendParentList(Uint32Buffer& serializedDef) const;

  // Append list of columns required by SPJ to instantiate child operations.
  Uint32 appendChildProjection(Uint32Buffer& serializedDef) const;

protected:
  bool m_isPrepared;

  bool m_diskInChildProjection;

private:
  bool isChildOf(const NdbQueryOperationDefImpl* parentOp) const;

  int addChild(NdbQueryOperationDefImpl* child);

  // Remove a linked child refering specified operation
  void removeChild(const NdbQueryOperationDefImpl*);

private:
  const NdbTableImpl& m_table;
  const char* const m_ident; // Optional name specified by aplication
  const Uint32 m_ix;         // Index of this operation within operation array
  Uint32       m_id;         // Operation id when materialized into queryTree.
                             // If op has index, index id is 'm_id-1'.

  // Optional (or default) options specified when building query:
  // - Scan order which may specify ascending or descending scan order
  // - Match type used for hinting on optimal inner-, outer-, semijoin exec.
  const NdbQueryOptionsImpl m_options;

  // parent pointer & child ptr. vector contains dependencies 
  // as defined with linkedValues
  NdbQueryOperationDefImpl* m_parent;
  Vector<NdbQueryOperationDefImpl*> m_children;

  // Params required by this operation
  Vector<const NdbParamOperandImpl*> m_params;

  // Column from this operation required by its child operations
  Vector<const NdbColumnImpl*> m_spjProjection;
}; // class NdbQueryOperationDefImpl


class NdbQueryScanOperationDefImpl :
  public NdbQueryOperationDefImpl
{
public:
  explicit NdbQueryScanOperationDefImpl (
                           const NdbTableImpl& table,
                           const NdbQueryOptionsImpl& options,
                           const char* ident,
                           Uint32      ix,
                           int& error);

  virtual bool isScanOperation() const
  { return true; }

protected:
  int serialize(Uint32Buffer& serializedDef,
                const NdbTableImpl& tableOrIndex);

  // Append pattern for creating complete range bounds to serialized code 
  virtual Uint32 appendBoundPattern(Uint32Buffer& serializedDef) const
  { return 0; }

  virtual Uint32 appendPrunePattern(Uint32Buffer& serializedDef) const
  { return 0; }

}; // class NdbQueryScanOperationDefImpl


class NdbQueryIndexScanOperationDefImpl : public NdbQueryScanOperationDefImpl
{
  friend class NdbQueryBuilder;  // Allow privat access from builder interface

public:
  virtual const NdbIndexImpl* getIndex() const
  { return &m_index; }

  virtual int serializeOperation(Uint32Buffer& serializedDef);

  virtual const NdbQueryIndexScanOperationDef& getInterface() const
  { return m_interface; }

  virtual NdbQueryOperationDef::Type getType() const
  { return NdbQueryOperationDef::OrderedIndexScan; }

  virtual int checkPrunable(const Uint32Buffer& keyInfo,
                            Uint32  shortestBound,
                            bool&   isPruned,
                            Uint32& hashValue) const;

  virtual const IndexBound* getBounds() const
  { return &m_bound; } 

protected:
  // Append pattern for creating complete range bounds to serialized code 
  virtual Uint32 appendBoundPattern(Uint32Buffer& serializedDef) const;

  virtual Uint32 appendPrunePattern(Uint32Buffer& serializedDef) const;

private:

  explicit NdbQueryIndexScanOperationDefImpl (
                           const NdbIndexImpl& index,
                           const NdbTableImpl& table,
                           const NdbQueryIndexBound* bound,
                           const NdbQueryOptionsImpl& options,
                           const char* ident,
                           Uint32      ix,
                           int& error);

  // Append pattern for creating a single bound value to serialized code 
  Uint32 appendBoundValue( Uint32Buffer& serializedDef,
                           NdbIndexScanOperation::BoundType type,
                           const NdbQueryOperandImpl* value,
                           int& paramCnt) const;

private:
  NdbQueryIndexScanOperationDef m_interface;
  const NdbIndexImpl& m_index;

  IndexBound m_bound;
}; // class NdbQueryIndexScanOperationDefImpl


class NdbQueryDefImpl
{
  friend class NdbQueryDef;

public:
  explicit NdbQueryDefImpl(const Vector<NdbQueryOperationDefImpl*>& operations,
                           const Vector<NdbQueryOperandImpl*>& operands,
                           int& error);
  ~NdbQueryDefImpl();

  // Entire query is a scan iff root operation is scan. 
  // May change in the future as we implement more complicated SPJ operations.
  bool isScanQuery() const
  { return m_operations[0]->isScanOperation(); }

  NdbQueryDef::QueryType getQueryType() const;

  Uint32 getNoOfOperations() const
  { return m_operations.size(); }

  // Get a specific NdbQueryOperationDef by ident specified
  // when the NdbQueryOperationDef was created.
  const NdbQueryOperationDefImpl& getQueryOperation(Uint32 index) const
  { return *m_operations[index]; } 

  const NdbQueryOperationDefImpl* getQueryOperation(const char* ident) const;

  const NdbQueryDef& getInterface() const
  { return m_interface; }

  Uint32Buffer& getSerialized()
  { return m_serializedDef; }

  const Uint32Buffer& getSerialized() const
  { return m_serializedDef; }

private:
  NdbQueryDef m_interface;

  Vector<NdbQueryOperationDefImpl*> m_operations;
  Vector<NdbQueryOperandImpl*> m_operands;
  Uint32Buffer m_serializedDef; 
}; // class NdbQueryDefImpl


class NdbQueryBuilderImpl
{
  friend class NdbQueryBuilder;

public:
  ~NdbQueryBuilderImpl();
  explicit NdbQueryBuilderImpl();

  const NdbQueryDefImpl* prepare();

  const NdbError& getNdbError() const;

  void setErrorCode(int aErrorCode);

private:
  bool hasError() const
  { return m_hasError; }

  NdbQueryOperand* addOperand(NdbQueryOperandImpl* operand);

  int takeOwnership(NdbQueryOperandImpl*);
  int takeOwnership(NdbQueryOperationDefImpl*);

  bool contains(const NdbQueryOperationDefImpl*);

  NdbQueryBuilder m_interface;
  NdbError m_error;

  Vector<NdbQueryOperationDefImpl*> m_operations;
  Vector<NdbQueryOperandImpl*> m_operands;
  Uint32 m_paramCnt;
  bool m_hasError;
}; // class NdbQueryBuilderImpl


// Implementation of NdbQueryOperand interface

// Baseclass for the QueryOperand implementation
class NdbQueryOperandImpl
{
  friend class NdbQueryBuilderImpl;
public:

  enum Kind {
    Linked,
    Param,
    Const
  };

  const NdbColumnImpl* getColumn() const
  { return m_column; }

  virtual int bindOperand(const NdbColumnImpl& column,
                          NdbQueryOperationDefImpl& operation)
  { if (m_column  && m_column != &column)
      // Already bounded to a different column
      return QRY_OPERAND_ALREADY_BOUND;
    m_column = &column;
    return 0;
  }

  Kind getKind() const
  { return m_kind; }

  virtual NdbQueryOperand& getInterface() = 0;

protected:
  friend NdbQueryBuilderImpl::~NdbQueryBuilderImpl();
  friend NdbQueryDefImpl::~NdbQueryDefImpl();

  virtual ~NdbQueryOperandImpl(){};

  NdbQueryOperandImpl(Kind kind)
    : m_column(0),
      m_kind(kind)
  {}

protected:
  const NdbColumnImpl* m_column;       // Initial NULL, assigned w/ bindOperand()

  const Kind m_kind;
}; // class NdbQueryOperandImpl


class NdbLinkedOperandImpl : public NdbQueryOperandImpl
{
  friend class NdbQueryBuilder;  // Allow privat access from builder interface

public:
  const NdbQueryOperationDefImpl& getParentOperation() const
  { return m_parentOperation; }

  // 'LinkedSrc' is index into parent op's spj-projection list where
  // the refered column value is available
  Uint32 getLinkedColumnIx() const
  { return m_parentColumnIx; }

  const NdbColumnImpl& getParentColumn() const
  { return *m_parentOperation.getSPJProjection()[m_parentColumnIx]; }

  virtual NdbQueryOperand& getInterface()
  { return m_interface; }

  virtual int bindOperand(const NdbColumnImpl& column,
                          NdbQueryOperationDefImpl& operation);

private:
  NdbLinkedOperandImpl (NdbQueryOperationDefImpl& parent, 
                        Uint32 columnIx)
   : NdbQueryOperandImpl(Linked),
     m_interface(*this), 
     m_parentOperation(parent),
     m_parentColumnIx(columnIx)
  {}

  NdbLinkedOperand m_interface;
  NdbQueryOperationDefImpl& m_parentOperation;
  const Uint32 m_parentColumnIx;
}; // class NdbLinkedOperandImpl


class NdbParamOperandImpl : public NdbQueryOperandImpl
{
  friend class NdbQueryBuilder;  // Allow privat access from builder interface

public:
  const char* getName() const
  { return m_name; }

  Uint32 getParamIx() const
  { return m_paramIx; }

  virtual NdbQueryOperand& getInterface()
  { return m_interface; }

  virtual int bindOperand(const NdbColumnImpl& column,
                          NdbQueryOperationDefImpl& operation);

private:
  NdbParamOperandImpl (const char* name, Uint32 paramIx)
   : NdbQueryOperandImpl(Param),
     m_interface(*this), 
     m_name(name),
     m_paramIx(paramIx)
  {}

  NdbParamOperand m_interface;
  const char* const m_name;     // Optional parameter name or NULL
  const Uint32 m_paramIx;
}; // class NdbParamOperandImpl


class NdbConstOperandImpl : public NdbQueryOperandImpl
{
  friend class NdbQueryBuilder;  // Allow privat access from builder interface
public:
  Uint32 getSizeInBytes() const
  { return m_converted.len; }
  const void* getAddr() const
  { return likely(m_converted.buffer==NULL) ? &m_converted.val : m_converted.buffer; }

  virtual NdbQueryOperand& getInterface()
  { return m_interface; }

  virtual int bindOperand(const NdbColumnImpl& column,
                          NdbQueryOperationDefImpl& operation);

protected:
  NdbConstOperandImpl ()
    : NdbQueryOperandImpl(Const),
      m_converted(),
      m_interface(*this)
  {}

  #define UNDEFINED_CONVERSION  \
  { return QRY_OPERAND_HAS_WRONG_TYPE; }

  virtual int convertUint8()  UNDEFINED_CONVERSION;
  virtual int convertInt8()   UNDEFINED_CONVERSION;
  virtual int convertUint16() UNDEFINED_CONVERSION;
  virtual int convertInt16()  UNDEFINED_CONVERSION;
  virtual int convertUint24() UNDEFINED_CONVERSION;
  virtual int convertInt24()  UNDEFINED_CONVERSION;
  virtual int convertUint32() UNDEFINED_CONVERSION;
  virtual int convertInt32()  UNDEFINED_CONVERSION;
  virtual int convertUint64() UNDEFINED_CONVERSION;
  virtual int convertInt64()  UNDEFINED_CONVERSION;
  virtual int convertFloat()  UNDEFINED_CONVERSION;
  virtual int convertDouble() UNDEFINED_CONVERSION

  virtual int convertUDec()   UNDEFINED_CONVERSION;
  virtual int convertDec()    UNDEFINED_CONVERSION;

  virtual int convertBit()    UNDEFINED_CONVERSION;
  virtual int convertChar()   UNDEFINED_CONVERSION;
  virtual int convertVChar()  UNDEFINED_CONVERSION;
  virtual int convertLVChar() UNDEFINED_CONVERSION;
  virtual int convertBin()    UNDEFINED_CONVERSION;
  virtual int convertVBin()   UNDEFINED_CONVERSION;
  virtual int convertLVBin()  UNDEFINED_CONVERSION;

  virtual int convertDate()   UNDEFINED_CONVERSION;
  virtual int convertDatetime() UNDEFINED_CONVERSION;
  virtual int convertTime()   UNDEFINED_CONVERSION;
  virtual int convertYear()   UNDEFINED_CONVERSION;
  virtual int convertTimestamp() UNDEFINED_CONVERSION;

  virtual int convert2ColumnType();

  class ConvertedValue {
  public:
    ConvertedValue()  : len(0), buffer(NULL) {};
    ~ConvertedValue() {
      if (buffer) delete[] ((char*)buffer);
    };

    char* getCharBuffer(Uint32 size) {
      char* dst = val.shortChar;
      if (unlikely(size > sizeof(val.shortChar))) {
        dst = new char[size];
        buffer = dst;
      }
      len = size;
      return dst;
    }

    STATIC_CONST(maxShortChar = 32);

    union
    {
      Uint8     uint8;
      Int8      int8;
      Uint16    uint16;
      Int16     int16;
      Uint32    uint32;
      Int32     int32;
      Uint64    uint64;
      Int64     int64;

      double    dbl;
      float     flt;

      char      shortChar[maxShortChar];
    } val;

    Uint32 len;
    void*  buffer;  // Optional; storage for converted value
  } m_converted;

private:
  NdbConstOperand m_interface;
}; // class NdbConstOperandImpl


#endif /* __cplusplus */
#endif