Ejemplo n.º 1
0
// -----------------------------------------------------------------------
// Given a column list providing identifiers for columns of this table,
// this method returns a list of VEG expressions and/or base columns that
// show the equivalence of base columns with index columns.
// -----------------------------------------------------------------------
void TableDesc::getEquivVEGCols (const ValueIdList& columnList,
                                 ValueIdList &VEGColumnList) const
{
    for (CollIndex i=0; i < columnList.entries(); i++)
    {
        ItemExpr   *ie = columnList[i].getItemExpr();
        BaseColumn *bc = NULL;

        switch (ie->getOperatorType())
        {
        case ITM_BASECOLUMN:
            bc = (BaseColumn *) ie;
            break;
        case ITM_INDEXCOLUMN:
            bc = (BaseColumn *) ((IndexColumn *) ie)->getDefinition().
                 getItemExpr();
            CMPASSERT(bc->getOperatorType() == ITM_BASECOLUMN);

            break;
        default:
            ABORT("Invalid argument to TableDesc::getEquivVEGCols()\n");
        }

        CMPASSERT(bc->getTableDesc() == this);
        VEGColumnList.insert(getColumnVEGList()[bc->getColNumber()]);
    }
}
Ejemplo n.º 2
0
NABoolean IndexDesc::isUniqueIndex() const
{

  return  getNAFileSet()->uniqueIndex();

#pragma nowarn(269)   // warning elimination 
  ValueIdList nonKeyColumnList;
#pragma warn(269)  // warning elimination 
  getNonKeyColumnList(nonKeyColumnList);
  
  // if there are some non-index-key columns(the key of base table),
  // then this is a unique index. The primary key of base table is
  // not needed to define the key of the index. It is, of course,
  // needed to be present in the index as a non-key column.
  if (nonKeyColumnList.entries() > 0)
    return TRUE;
  else
    return FALSE;
}
short ProbeCache::codeGen(Generator *generator)
{
  ExpGenerator * exp_gen = generator->getExpGenerator();
  Space * space = generator->getSpace();

  MapTable * last_map_table = generator->getLastMapTable();

  ex_cri_desc * given_desc
    = generator->getCriDesc(Generator::DOWN);

  ex_cri_desc * returned_desc
    = new(space) ex_cri_desc(given_desc->noTuples() + 1, space);

  // cri descriptor for work atp has 5 entries:
  // entry #0 for const
  // entry #1 for temp
  // entry #2 for hash value of probe input data in Probe Cache Manager
  // entry #3 for encoded probe input data in Probe Cache Manager
  // enrry #4 for inner table row data in this operator's cache buffer
  Int32 work_atp = 1;
  ex_cri_desc * work_cri_desc = new(space) ex_cri_desc(5, space);
  unsigned short hashValIdx          = 2; 
  unsigned short encodedProbeDataIdx = 3;
  unsigned short innerRowDataIdx     = 4;

    // generate code for child tree, and get its tdb and explain tuple.
  child(0)->codeGen(generator);
  ComTdb * child_tdb = (ComTdb *)(generator->getGenObj());
  ExplainTuple *childExplainTuple = generator->getExplainTuple();


  //////////////////////////////////////////////////////
  // Generate up to 4 runtime expressions.
  //////////////////////////////////////////////////////

  // Will use child's char. inputs (+ execution count) for the next
  // two runtime expressions.
  ValueIdList inputsToUse = child(0).getGroupAttr()->getCharacteristicInputs();
  
  inputsToUse.insert(generator->getOrAddStatementExecutionCount());

  // Expression #1 gets the hash value of the probe input data
  ValueIdList hvAsList;

  // Executor has hard-coded assumption that the result is long, 
  // so add a Cast node to convert result to a long.

  ItemExpr *probeHashAsIe = new (generator->wHeap())
    HashDistPartHash(inputsToUse.rebuildExprTree(ITM_ITEM_LIST));

  probeHashAsIe->bindNode(generator->getBindWA());

  NumericType &nTyp = (NumericType &)probeHashAsIe->getValueId().getType();
  GenAssert(nTyp.isSigned() == FALSE,
            "Unexpected signed HashDistPartHash.");

  GenAssert(probeHashAsIe->getValueId().getType().supportsSQLnullLogical()
            == FALSE, "Unexpected nullable HashDistPartHash.");

  ItemExpr *hvAsIe = new (generator->wHeap()) Cast(
       probeHashAsIe, 
       new (generator->wHeap()) 
            SQLInt(FALSE,   // false == unsigned.
                   FALSE    // false == not nullable.
                  ));

  hvAsIe->bindNode(generator->getBindWA());

  hvAsList.insert(hvAsIe->getValueId());

  ex_expr *hvExpr   = NULL;
  ULng32 hvLength;
  exp_gen->generateContiguousMoveExpr(
              hvAsList,
              0, // don't add convert node
              work_atp,
              hashValIdx,
              ExpTupleDesc::SQLARK_EXPLODED_FORMAT,
              hvLength,
              &hvExpr);

  GenAssert(hvLength == sizeof(Lng32),
            "Unexpected length of result of hash function.");

  // Expression #2 encodes the probe input data for storage in 
  // the ProbeCacheManager.

  ValueIdList encodeInputAsList;

  CollIndex inputListIndex;
  for (inputListIndex = 0; 
       inputListIndex < inputsToUse.entries(); 
       inputListIndex++) {   

    ItemExpr *inputIe = 
         (inputsToUse[inputListIndex].getValueDesc())->getItemExpr();

    if (inputIe->getValueId().getType().getVarLenHdrSize() > 0)
      {
        // This logic copied from Sort::codeGen().
        // Explode varchars by moving them to a fixed field
        // whose length is equal to the max length of varchar.
        // 5/8/98: add support for VARNCHAR

        const CharType& char_type =
          (CharType&)(inputIe->getValueId().getType());

	if (!CollationInfo::isSystemCollation(char_type.getCollation()))
	{
	  inputIe = new(generator->wHeap())
              Cast (inputIe,
                    (new(generator->wHeap())
                      SQLChar(
		          CharLenInfo(char_type.getStrCharLimit(), char_type.getDataStorageSize()),
                          char_type.supportsSQLnull(),
                          FALSE, FALSE, FALSE,
                          char_type.getCharSet(),
                          char_type.getCollation(),
                          char_type.getCoercibility()
                              )
                    )
                   );
	}
      }

    CompEncode * enode = new(generator->wHeap()) 
      CompEncode(inputIe, FALSE /* ascend/descend doesn't matter*/);

    enode->bindNode(generator->getBindWA());
    encodeInputAsList.insert(enode->getValueId());
  }

  ex_expr *encodeInputExpr = NULL;
  ULng32 encodedInputLength;
  exp_gen->generateContiguousMoveExpr(encodeInputAsList, 
                              0, //don't add conv nodes
                              work_atp, encodedProbeDataIdx,
                              ExpTupleDesc::SQLARK_EXPLODED_FORMAT,
                              encodedInputLength, &encodeInputExpr);


  // Expression #3 moves the inner table data into a buffer pool.  
  // This is also the tuple returned to ProbeCache's parent. 

  ex_expr * innerRecExpr = NULL;
  ValueIdList innerTableAsList = getGroupAttr()->getCharacteristicOutputs();

  //////////////////////////////////////////////////////
  // Describe the returned row and add the returned 
  // values to the map table.
  //////////////////////////////////////////////////////

  // determine internal format
  NABoolean useCif = FALSE;
  ExpTupleDesc::TupleDataFormat tupleFormat = generator->getInternalFormat();
  //tupleFormat = determineInternalFormat( innerTableAsList, this, useCif,generator);

  ULng32 innerRecLength = 0;
  ExpTupleDesc * innerRecTupleDesc = 0;
  MapTable * returnedMapTable = NULL;

  exp_gen->generateContiguousMoveExpr(innerTableAsList, 
                              -1, // do add conv nodes 
			      work_atp, innerRowDataIdx,
			      tupleFormat,
			      innerRecLength, &innerRecExpr,
			      &innerRecTupleDesc, ExpTupleDesc::SHORT_FORMAT,
                              &returnedMapTable);

  returned_desc->setTupleDescriptor(returned_desc->noTuples() - 1, 
        innerRecTupleDesc);

  // remove all appended map tables and return the returnedMapTable
  generator->removeAll(last_map_table);
  generator->appendAtEnd(returnedMapTable);
  // This returnedMapTable will contain the value ids that are being returned 
  // (the inner table probed).

  // Massage the atp and atp_index of the innerTableAsList.
  for (CollIndex i = 0; i < innerTableAsList.entries(); i++)
    {
      ValueId innerValId = innerTableAsList[i];

      Attributes *attrib =
	generator->getMapInfo(innerValId)->getAttr();

      // All reference to the returned values from this point on
      // will be at atp = 0, atp_index = last entry in returned desc.
      attrib->setAtp(0);
      attrib->setAtpIndex(returned_desc->noTuples() - 1);
    }

  // Expression #4 is a selection predicate, to be applied
  // before returning rows to the parent

  ex_expr * selectPred = NULL;

  if (!selectionPred().isEmpty())
    {
      ItemExpr * selPredTree =
        selectionPred().rebuildExprTree(ITM_AND,TRUE,TRUE);
      exp_gen->generateExpr(selPredTree->getValueId(),
                            ex_expr::exp_SCAN_PRED,
                            &selectPred);
    }

  //////////////////////////////////////////////////////
  // Prepare params for ComTdbProbeCache.
  //////////////////////////////////////////////////////

  queue_index pDownSize = (queue_index)getDefault(GEN_PROBE_CACHE_SIZE_DOWN);
  queue_index pUpSize   = (queue_index)getDefault(GEN_PROBE_CACHE_SIZE_UP);

  // Make sure that the ProbeCache queues can support the childs queues.
  if(pDownSize < child_tdb->getInitialQueueSizeDown()) {
    pDownSize = child_tdb->getInitialQueueSizeDown();
    pDownSize = MINOF(pDownSize, 32768);
  }
  if(pUpSize < child_tdb->getInitialQueueSizeUp()) {
    pUpSize = child_tdb->getInitialQueueSizeUp();
    pUpSize = MINOF(pUpSize, 32768);
  }

  ULng32 pcNumEntries = numCachedProbes_;
  
  // Number of entries in the probe cache cannot be less than 
  // max parent down queue size.  Before testing and adjusting the 
  // max queue size, it is necessary to make sure it is a power of
  // two, rounding up if necessary.  This is to match the logic in
  // ex_queue::resize.

  queue_index pdq2 = 1;
  queue_index bits = pDownSize;
  while (bits && pdq2 < pDownSize) {
    bits = bits  >> 1;
    pdq2 = pdq2 << 1;
  }
  if (pcNumEntries < pdq2)
    pcNumEntries = pdq2;

  numInnerTuples_ = getDefault(GEN_PROBE_CACHE_NUM_INNER);

  if (innerRecExpr == NULL)
    {
      // For semi-join and anti-semi-join, executor need not allocate
      // a buffer.  Set the tdb's buffer size to 0 to be consistent.
      numInnerTuples_ = 0;
    }
  else if (numInnerTuples_ == 0)
    {
      // Handle special value, 0, which tells code gen to 
      // decided on buffer size: i.e., large enough to accomodate
      // all parent up queue entries and all probe cache entries 
      // having a different inner table row.

      // As we did for the down queue, make sure the up queue size 
      // specified is a power of two.

      queue_index puq2 = 1;
      queue_index bits = pUpSize;
      while (bits && puq2 < pUpSize) {
        bits = bits  >> 1;
        puq2 = puq2 << 1;
      }
      numInnerTuples_ = puq2 + pcNumEntries;
    }
Ejemplo n.º 4
0
static short ft_codegen(Generator *generator,
                        RelExpr &relExpr,
                        ComTdbFastExtract *&newTdb,
                        Cardinality estimatedRowCount,
                        char * targetName,
                        char * hdfsHost,
                        Int32 hdfsPort,
                        char * hiveTableName,
                        char * delimiter,
                        char * header,
                        char * nullString,
                        char * recordSeparator,
                        ULng32 downQueueMaxSize,
                        ULng32 upQueueMaxSize,
                        ULng32 outputBufferSize,
                        ULng32 requestBufferSize,
                        ULng32 replyBufferSize,
                        ULng32 numOutputBuffers,
                        ComTdb * childTdb,
                        NABoolean isSequenceFile)
{
  CmpContext *cmpContext = generator->currentCmpContext();
  Space *space = generator->getSpace();
  ExpGenerator *exp_gen = generator->getExpGenerator();
  MapTable *map_table = generator->getMapTable();
  MapTable *last_map_table = generator->getLastMapTable();
  ex_expr *input_expr = NULL;
  ex_expr *output_expr = NULL;
  ex_expr * childData_expr = NULL ;
  ex_expr * cnvChildData_expr = NULL ;
  ULng32 i;
  ULng32 requestRowLen = 0;
  ULng32 outputRowLen = 0;
  ULng32 childDataRowLen = 0;
  ULng32 cnvChildDataRowLen = 0;
  ExpTupleDesc *requestTupleDesc = NULL;

  ExpTupleDesc *outputTupleDesc = NULL;
  ExpTupleDesc *childDataTupleDesc = NULL;
  ExpTupleDesc *cnvChildDataTupleDesc = NULL;
  newTdb = NULL;

  OperatorTypeEnum relExprType = relExpr.getOperatorType();
  GenAssert(relExprType == REL_FAST_EXTRACT, "Unexpected RelExpr at FastExtract codegen")
  FastExtract * fastExtract = (FastExtract *) &relExpr;

  const Int32 workAtpNumber = 1;
  ex_cri_desc *given_desc = generator->getCriDesc(Generator::DOWN);
  ex_cri_desc *returned_desc = NULL;
  ex_cri_desc *work_cri_desc = NULL;

  returned_desc = given_desc;

  // Setup local variables related to the work ATP
  unsigned short numWorkTupps = 0;
  unsigned short childDataTuppIndex = 0;
  unsigned short cnvChildDataTuppIndex = 0;

  numWorkTupps = 3;
  childDataTuppIndex = numWorkTupps - 1 ;
  numWorkTupps ++;
  cnvChildDataTuppIndex = numWorkTupps - 1;
  work_cri_desc = new (space) ex_cri_desc(numWorkTupps, space);

  ExpTupleDesc::TupleDataFormat childReqFormat = ExpTupleDesc::SQLMX_ALIGNED_FORMAT;

  ValueIdList childDataVids;
  ValueIdList cnvChildDataVids;
  const ValueIdList& childVals = fastExtract->getSelectList();

  for (i = 0; i < childVals.entries(); i++)
  {
    ItemExpr &inputExpr = *(childVals[i].getItemExpr());
    const NAType &formalType = childVals[i].getType();
    ItemExpr *lmExpr = NULL;
    ItemExpr *lmExpr2 = NULL;
    int res;

    lmExpr = &inputExpr; //CreateCastExpr(inputExpr, *inputExpr.getValueId().getType().newCopy(), cmpContext);

    res = CreateAllCharsExpr(formalType, // [IN] Child output type
        *lmExpr, // [IN] Actual input value
        cmpContext, // [IN] Compilation context
        lmExpr2 // [OUT] Returned expression
        );

    GenAssert(res == 0 && lmExpr != NULL,
        "Error building expression tree for LM child Input value");

    lmExpr->bindNode(generator->getBindWA());
    childDataVids.insert(lmExpr->getValueId());
    if (lmExpr2)
    {
      lmExpr2->bindNode(generator->getBindWA());
      cnvChildDataVids.insert(lmExpr2->getValueId());
    }


  } // for (i = 0; i < childVals.entries(); i++)

  if (childDataVids.entries() > 0 &&
    cnvChildDataVids.entries()>0)  //-- convertedChildDataVids
  {
    exp_gen->generateContiguousMoveExpr (
      childDataVids,                         //childDataVids// [IN] source ValueIds
      TRUE,                                 // [IN] add convert nodes?
      workAtpNumber,                        // [IN] target atp number (0 or 1)
      childDataTuppIndex,                   // [IN] target tupp index
      childReqFormat,                       // [IN] target tuple data format
      childDataRowLen,                      // [OUT] target tuple length
      &childData_expr,                  // [OUT] move expression
      &childDataTupleDesc,                  // [optional OUT] target tuple desc
      ExpTupleDesc::LONG_FORMAT             // [optional IN] target desc format
      );

    exp_gen->processValIdList (
       cnvChildDataVids,                              // [IN] ValueIdList
       ExpTupleDesc::SQLARK_EXPLODED_FORMAT,  // [IN] tuple data format
       cnvChildDataRowLen,                          // [OUT] tuple length
       workAtpNumber,                                     // [IN] atp number
       cnvChildDataTuppIndex,         // [IN] index into atp
       &cnvChildDataTupleDesc,                      // [optional OUT] tuple desc
       ExpTupleDesc::LONG_FORMAT              // [optional IN] tuple desc format
       );
  }
  //
  // Add the tuple descriptor for request values to the work ATP
  //
  work_cri_desc->setTupleDescriptor(childDataTuppIndex, childDataTupleDesc);
  work_cri_desc->setTupleDescriptor(cnvChildDataTuppIndex, cnvChildDataTupleDesc);

  // We can now remove all appended map tables
  generator->removeAll(last_map_table);



  ComSInt32 maxrs = 0;
  UInt32 flags = 0;
  UInt16 numIoBuffers = (UInt16)(ActiveSchemaDB()->getDefaults()).getAsLong(FAST_EXTRACT_IO_BUFFERS);
  UInt16 ioTimeout = (UInt16)(ActiveSchemaDB()->getDefaults()).getAsLong(FAST_EXTRACT_IO_TIMEOUT_SEC);

  Int64 hdfsBufSize = (Int64)CmpCommon::getDefaultNumeric(HDFS_IO_BUFFERSIZE);
  hdfsBufSize = hdfsBufSize * 1024; // convert to bytes
  Int16 replication =  (Int16)CmpCommon::getDefaultNumeric(HDFS_REPLICATION);


  // Create a TDB
  ComTdbFastExtract *tdb = new (space) ComTdbFastExtract (
    flags,
    estimatedRowCount,
    targetName,
    hdfsHost,
    hdfsPort,
    hiveTableName,
    delimiter,
    header,
    nullString,
    recordSeparator,
    given_desc,
    returned_desc,
    work_cri_desc,
    downQueueMaxSize,
    upQueueMaxSize,
    (Lng32) numOutputBuffers,
    outputBufferSize,
    numIoBuffers,
    ioTimeout,
    input_expr,
    output_expr,
    requestRowLen,
    outputRowLen,
    childData_expr,
    childTdb,
    space,
    childDataTuppIndex,
    cnvChildDataTuppIndex,
    childDataRowLen,
    hdfsBufSize,
    replication
    );

  tdb->setSequenceFile(isSequenceFile);
  tdb->setHdfsCompressed(CmpCommon::getDefaultNumeric(TRAF_UNLOAD_HDFS_COMPRESS)!=0);

  tdb->setSkipWritingToFiles(CmpCommon::getDefault(TRAF_UNLOAD_SKIP_WRITING_TO_FILES) == DF_ON);
  tdb->setBypassLibhdfs(CmpCommon::getDefault(TRAF_UNLOAD_BYPASS_LIBHDFS) == DF_ON);
  generator->initTdbFields(tdb);

  // Generate EXPLAIN info.
  if (!generator->explainDisabled())
  {
    generator->setExplainTuple(relExpr.addExplainInfo(tdb, 0, 0, generator));
  }

  // Tell the generator about our in/out rows and the new TDB
  generator->setCriDesc(given_desc, Generator::DOWN);
  generator->setCriDesc(returned_desc, Generator::UP);
  generator->setGenObj(&relExpr, tdb);


  // Return a TDB pointer to the caller
  newTdb = tdb;

  return 0;

} // ft_codegen()
void ItemExprList::insertTree(ItemExpr *tree,
			      OperatorTypeEnum backBoneType,
			      NABoolean flattenSBQ, NABoolean flattenUDF)
{
  if (tree->getOperatorType() == backBoneType) 
    {
      for (Int32 i = 0; i < tree->getArity(); i++)
        {
          // Check for NULL list for right linear trees. That is, arity may be 
          // two, but second child is NULL.
          ItemExpr *child = tree->child(i);
          if (child)
            insertTree(tree->child(i), backBoneType, flattenSBQ, flattenUDF);
        }
    } 
  else if (tree->getOperatorType() == ITM_ONE_ROW)
  {
    Aggregate *agr = (Aggregate *)tree;

    if (agr->isOneRowTransformed_)
    {
      for (Int32 i = 0; i < tree->getArity(); i++)
        insertTree(tree->child(i), backBoneType, flattenSBQ, flattenUDF); 
    }
    else
    {
      // do nothing, postpone this processing until OneRow transformation
      // is done
    }
  }
  else if ((flattenSBQ AND tree->isASubquery()) OR 
           (flattenUDF AND 
           (tree->getOperatorType() == ITM_USER_DEF_FUNCTION)) AND
           (NOT tree->nodeIsTransformed()))
          // Added the extra check for transformation above to avoid any issues
          // where we might flatten a subquery/MVF a second time around while 
          // we deal with ValueIdProxies. 
          // The ValueIdProxy->needToTransformChild()
          // flag should be sufficient, but it never hurts to be safe.
    {
      ValueIdList cols;
      NABoolean haveRDesc(FALSE);

      if (tree->isASubquery())
      {
        // flatten the subquery select list
        RETDesc *retDesc = ((Subquery*)tree)->getSubquery()->getRETDesc();
        if (retDesc)
        {
          retDesc->getColumnList()->getValueIdList(cols);
          if (cols.entries() > 1)
          {
            haveRDesc = TRUE;
          }
        }
 
      }
      else if (tree->getOperatorType() == ITM_USER_DEF_FUNCTION)
      {
        // flatten the UDF by adding the additional outputs to the tree 
        const RoutineDesc *rDesc = ((UDFunction *)tree)->getRoutineDesc();
        if (rDesc && rDesc->getOutputColumnList().entries() > 1)
        {
          cols = rDesc->getOutputColumnList();
          haveRDesc = TRUE;
        }
      }

      if (haveRDesc == TRUE)
      {
        for (CollIndex i = 0; i < cols.entries(); i++)

        {
           ValueId  proxyId;

           proxyId = cols[i];

           // We create a ValueIdProxy for each element in the subquery's
           // select list or for each output parameter of a MVF. The first
           // one of these will be marked to be transformed. This allows
           // us to get the correct degree of statements containing MVFs or
           // subquery with degree > 1 at bind time. 
           ValueIdProxy *proxyOutput = 
                 new (CmpCommon::statementHeap())
                      ValueIdProxy( tree->getValueId(), 
                                    proxyId,
                                    i);


           proxyOutput->synthTypeAndValueId();

           // Make sure we transform the subquery or MVF 
           if (i == 0 ) proxyOutput->setTransformChild(TRUE);

           insert(proxyOutput);
        }

      }
      else
        insert(tree); // we are processing a valueId of a UDFunction 
                      // or subquery before we have bound it. Just insert 
                      // its valueId and we'll have to deal with it later..
    }
  else
    insert(tree);
}
static short ft_codegen(Generator *generator,
                        RelExpr &relExpr,
                        ComTdbFastExtract *&newTdb,
                        Cardinality estimatedRowCount,
                        char * targetName,
                        char * hdfsHost,
                        Int32 hdfsPort,
                        char * hiveTableName,
                        char * delimiter,
                        char * header,
                        char * nullString,
                        char * recordSeparator,
                        ULng32 downQueueMaxSize,
                        ULng32 upQueueMaxSize,
                        ULng32 outputBufferSize,
                        ULng32 requestBufferSize,
                        ULng32 replyBufferSize,
                        ULng32 numOutputBuffers,
                        ComTdb * childTdb,
                        NABoolean isSequenceFile)
{
  CmpContext *cmpContext = generator->currentCmpContext();
  Space *space = generator->getSpace();
  ExpGenerator *exp_gen = generator->getExpGenerator();
  MapTable *map_table = generator->getMapTable();
  MapTable *last_map_table = generator->getLastMapTable();
  ex_expr *input_expr = NULL;
  ex_expr *output_expr = NULL;
  ex_expr * childData_expr = NULL ;
  ex_expr * cnvChildData_expr = NULL ;
  ULng32 i;
  ULng32 requestRowLen = 0;
  ULng32 outputRowLen = 0;
  ULng32 childDataRowLen = 0;
  ULng32 cnvChildDataRowLen = 0;
  ExpTupleDesc *requestTupleDesc = NULL;

  ExpTupleDesc *outputTupleDesc = NULL;
  ExpTupleDesc *childDataTupleDesc = NULL;
  ExpTupleDesc *cnvChildDataTupleDesc = NULL;
  newTdb = NULL;

  OperatorTypeEnum relExprType = relExpr.getOperatorType();
  GenAssert(relExprType == REL_FAST_EXTRACT, "Unexpected RelExpr at FastExtract codegen")
  FastExtract * fastExtract = (FastExtract *) &relExpr;

  const Int32 workAtpNumber = 1;
  ex_cri_desc *given_desc = generator->getCriDesc(Generator::DOWN);
  ex_cri_desc *returned_desc = NULL;
  ex_cri_desc *work_cri_desc = NULL;

  returned_desc = given_desc;

  // Setup local variables related to the work ATP
  unsigned short numWorkTupps = 0;
  unsigned short childDataTuppIndex = 0;
  unsigned short cnvChildDataTuppIndex = 0;

  numWorkTupps = 3;
  childDataTuppIndex = numWorkTupps - 1 ;
  numWorkTupps ++;
  cnvChildDataTuppIndex = numWorkTupps - 1;
  work_cri_desc = new (space) ex_cri_desc(numWorkTupps, space);

  ExpTupleDesc::TupleDataFormat childReqFormat = ExpTupleDesc::SQLMX_ALIGNED_FORMAT;

  ValueIdList childDataVids;
  ValueIdList cnvChildDataVids;
  const ValueIdList& childVals = fastExtract->getSelectList();

  const NATable *hiveNATable = NULL;
  const NAColumnArray *hiveNAColArray = NULL;

  // hiveInsertErrMode: 
  //    if 0, do not do error checks.
  //    if 1, do error check and return error.
  //    if 2, do error check and ignore row, if error
  //    if 3, insert null if an error occurs
  Lng32 hiveInsertErrMode = 0;
  if ((fastExtract) && (fastExtract->isHiveInsert()) &&
      (fastExtract->getHiveTableDesc()) &&
      (fastExtract->getHiveTableDesc()->getNATable()) &&
      ((hiveInsertErrMode = CmpCommon::getDefaultNumeric(HIVE_INSERT_ERROR_MODE)) > 0))
    {
      hiveNATable = fastExtract->getHiveTableDesc()->getNATable();
      hiveNAColArray = &hiveNATable->getNAColumnArray();
    }

  for (i = 0; i < childVals.entries(); i++)
  {
    ItemExpr &inputExpr = *(childVals[i].getItemExpr());
    const NAType &formalType = childVals[i].getType();
    ItemExpr *lmExpr = NULL;
    ItemExpr *lmExpr2 = NULL;
    int res;

    lmExpr = &inputExpr; 
    lmExpr = lmExpr->bindNode(generator->getBindWA());
    if (!lmExpr || generator->getBindWA()->errStatus())
      {
        GenAssert(0, "lmExpr->bindNode failed");
      }

    // Hive insert converts child data into string format and inserts
    // it into target table.
    // If child type can into an error during conversion, then
    // add a Cast to convert from child type to target type before
    // converting to string format to be inserted.
    if (hiveNAColArray)
      {
        const NAColumn *hiveNACol = (*hiveNAColArray)[i];
        const NAType *hiveNAType = hiveNACol->getType();
        // if tgt type was a hive 'string', do not return a conversion err
        if ((lmExpr->getValueId().getType().errorsCanOccur(*hiveNAType)) &&
            (NOT ((DFS2REC::isSQLVarChar(hiveNAType->getFSDatatype())) &&
                  (((SQLVarChar*)hiveNAType)->wasHiveString()))))
          {
            ItemExpr *newExpr = 
              new(generator->wHeap()) Cast(lmExpr, hiveNAType);
            newExpr = newExpr->bindNode(generator->getBindWA());
            if (!newExpr || generator->getBindWA()->errStatus())
              {
                GenAssert(0, "newExpr->bindNode failed");
              }
            
            if (hiveInsertErrMode == 3)
              ((Cast*)newExpr)->setConvertNullWhenError(TRUE);
            
            lmExpr = newExpr;
          }
      }

    res = CreateAllCharsExpr(formalType, // [IN] Child output type
        *lmExpr, // [IN] Actual input value
        cmpContext, // [IN] Compilation context
        lmExpr2 // [OUT] Returned expression
        );

    GenAssert(res == 0 && lmExpr != NULL,
        "Error building expression tree for LM child Input value");

    childDataVids.insert(lmExpr->getValueId());
    if (lmExpr2)
    {
      lmExpr2->bindNode(generator->getBindWA());
      cnvChildDataVids.insert(lmExpr2->getValueId());
    }


  } // for (i = 0; i < childVals.entries(); i++)

  if (childDataVids.entries() > 0 &&
    cnvChildDataVids.entries()>0)  //-- convertedChildDataVids
  {
    UInt16 pcm = exp_gen->getPCodeMode();
    if ((hiveNAColArray) &&
        (hiveInsertErrMode == 3))
      {
        // if error mode is 3 (mode null when error), disable pcode.
        // this feature is currently not being handled by pcode.
        // (added as part of JIRA 1920 in FileScan::codeGenForHive).
        exp_gen->setPCodeMode(ex_expr::PCODE_NONE);
      }

    exp_gen->generateContiguousMoveExpr (
      childDataVids,                         //childDataVids// [IN] source ValueIds
      TRUE,                                 // [IN] add convert nodes?
      workAtpNumber,                        // [IN] target atp number (0 or 1)
      childDataTuppIndex,                   // [IN] target tupp index
      childReqFormat,                       // [IN] target tuple data format
      childDataRowLen,                      // [OUT] target tuple length
      &childData_expr,                  // [OUT] move expression
      &childDataTupleDesc,                  // [optional OUT] target tuple desc
      ExpTupleDesc::LONG_FORMAT             // [optional IN] target desc format
      );

    exp_gen->setPCodeMode(pcm);

    exp_gen->processValIdList (
       cnvChildDataVids,                              // [IN] ValueIdList
       ExpTupleDesc::SQLARK_EXPLODED_FORMAT,  // [IN] tuple data format
       cnvChildDataRowLen,                          // [OUT] tuple length
       workAtpNumber,                                     // [IN] atp number
       cnvChildDataTuppIndex,         // [IN] index into atp
       &cnvChildDataTupleDesc,                      // [optional OUT] tuple desc
       ExpTupleDesc::LONG_FORMAT              // [optional IN] tuple desc format
       );
  }
  //
  // Add the tuple descriptor for request values to the work ATP
  //
  work_cri_desc->setTupleDescriptor(childDataTuppIndex, childDataTupleDesc);
  work_cri_desc->setTupleDescriptor(cnvChildDataTuppIndex, cnvChildDataTupleDesc);

  // We can now remove all appended map tables
  generator->removeAll(last_map_table);



  ComSInt32 maxrs = 0;
  UInt32 flags = 0;
  UInt16 numIoBuffers = (UInt16)(ActiveSchemaDB()->getDefaults()).getAsLong(FAST_EXTRACT_IO_BUFFERS);
  UInt16 ioTimeout = (UInt16)(ActiveSchemaDB()->getDefaults()).getAsLong(FAST_EXTRACT_IO_TIMEOUT_SEC);

  Int64 hdfsBufSize = (Int64)CmpCommon::getDefaultNumeric(HDFS_IO_BUFFERSIZE);
  hdfsBufSize = hdfsBufSize * 1024; // convert to bytes
  Int16 replication =  (Int16)CmpCommon::getDefaultNumeric(HDFS_REPLICATION);


  // Create a TDB
  ComTdbFastExtract *tdb = new (space) ComTdbFastExtract (
    flags,
    estimatedRowCount,
    targetName,
    hdfsHost,
    hdfsPort,
    hiveTableName,
    delimiter,
    header,
    nullString,
    recordSeparator,
    given_desc,
    returned_desc,
    work_cri_desc,
    downQueueMaxSize,
    upQueueMaxSize,
    (Lng32) numOutputBuffers,
    outputBufferSize,
    numIoBuffers,
    ioTimeout,
    input_expr,
    output_expr,
    requestRowLen,
    outputRowLen,
    childData_expr,
    childTdb,
    space,
    childDataTuppIndex,
    cnvChildDataTuppIndex,
    childDataRowLen,
    hdfsBufSize,
    replication
    );

  tdb->setSequenceFile(isSequenceFile);
  tdb->setHdfsCompressed(CmpCommon::getDefaultNumeric(TRAF_UNLOAD_HDFS_COMPRESS)!=0);

  tdb->setSkipWritingToFiles(CmpCommon::getDefault(TRAF_UNLOAD_SKIP_WRITING_TO_FILES) == DF_ON);
  tdb->setBypassLibhdfs(CmpCommon::getDefault(TRAF_UNLOAD_BYPASS_LIBHDFS) == DF_ON);

  if ((hiveNAColArray) &&
      (hiveInsertErrMode == 2))
    {
      tdb->setContinueOnError(TRUE);
    }

  generator->initTdbFields(tdb);

  // Generate EXPLAIN info.
  if (!generator->explainDisabled())
  {
    generator->setExplainTuple(relExpr.addExplainInfo(tdb, 0, 0, generator));
  }

  // Tell the generator about our in/out rows and the new TDB
  generator->setCriDesc(given_desc, Generator::DOWN);
  generator->setCriDesc(returned_desc, Generator::UP);
  generator->setGenObj(&relExpr, tdb);


  // Return a TDB pointer to the caller
  newTdb = tdb;

  return 0;

} // ft_codegen()
Ejemplo n.º 7
0
short ExpGenerator::buildKeyInfo(keyRangeGen ** keyInfo, // out -- generated object
                                 Generator * generator,
                                 const NAColumnArray & keyColumns,
                                 const ValueIdList & listOfKeyColumns,
                                 const ValueIdList & beginKeyPred,
                                 const ValueIdList & endKeyPred,
                                 const SearchKey * searchKey,
                                 const MdamKey * mdamKeyPtr,
                                 const NABoolean reverseScan,
                                 unsigned short keytag,
                                 const ExpTupleDesc::TupleDataFormat tf,
                                 // the next few parameters are here
                                 // as part of a horrible kludge for
                                 // the PartitionAccess::codeGen()
                                 // method, which lacks a SearchKey
                                 // object and therefore exposes
                                 // things like the exclusion
                                 // expressions; with luck, later work
                                 // in the Optimizer will result in a
                                 // much cleaner interface
                                 const NABoolean useTheHorribleKludge,
                                 ItemExpr * beginKeyExclusionExpr,
                                 ItemExpr * endKeyExclusionExpr,

                                 ex_expr_lean ** unique_key_expr,
                                 ULng32 *uniqueKeyLen,
                                 NABoolean doKeyEncodeOpt,
                                 Lng32 * firstKeyColOffset,
				 Int32 in_key_atp_index
                                 )

{
  Space * space = generator->getSpace();

  const Int32 work_atp = 1;
  const Int32 key_atp_index = (in_key_atp_index <= 0 ? 2 : in_key_atp_index);
  const Int32 exclude_flag_atp_index = 3;
  const Int32 data_conv_error_atp_index = 4;
  const Int32 key_column_atp_index = 5; // used only for Mdam
  const Int32 key_column2_atp_index = 6; // used only for Mdam MDAM_BETWEEN pred;
                                         //   code in BiLogic::mdamPredGenSubrange
                                         //   and MdamColumn::buildDisjunct
                                         //   requires this to be 1 more than
                                         //   key_column_atp_index
  ULng32 keyLen;

  // add an entry to the map table for work Atp
  MapTable *keyBufferPartMapTable = generator->appendAtEnd();

  // generate a temporary variable, which will be used for handling
  // data conversion errors during key building
  ValueIdList temp_varb_list;

  ItemExpr * dataConversionErrorFlag = new(generator->wHeap())
    HostVar("_sys_dataConversionErrorFlag",
            new(generator->wHeap()) SQLInt(TRUE,FALSE), // int not null
            TRUE);
  ULng32 temp_varb_tupp_len;

  dataConversionErrorFlag->bindNode(generator->getBindWA());
  temp_varb_list.insert(dataConversionErrorFlag->getValueId());
  processValIdList(temp_varb_list,
                   ExpTupleDesc::SQLARK_EXPLODED_FORMAT,
                   temp_varb_tupp_len,  // out
                   work_atp,
                   data_conv_error_atp_index);

  NABoolean doEquiKeyPredOpt = FALSE;
#ifdef _DEBUG
  if (getenv("DO_EQUI_KEY_PRED_OPT"))
    doEquiKeyPredOpt 
      = (searchKey ? searchKey->areAllChosenPredsEqualPreds() : FALSE);
#endif
  if (mdamKeyPtr == NULL)
    {
      // check to see if there is a begin key expression; if there
      // isn't, don't generate a key object
      if (beginKeyPred.entries() == 0)
        *keyInfo = 0;
      else
        {
          // For subset and range operators, generate the begin key
          // expression, end key expression, begin key exclusion expression
          // and end key exclusion expression.  For unique operators,
          // generate only the begin key exppression.
          ex_expr *bk_expr = 0;
          ex_expr *ek_expr = 0;
          ex_expr *bk_excluded_expr = 0;
          ex_expr *ek_excluded_expr = 0;
          
          short bkey_excluded = 0;
          short ekey_excluded = 0;
          
          generateKeyExpr(keyColumns,
              beginKeyPred,
              work_atp,
              key_atp_index,
              dataConversionErrorFlag,
              tf,
              keyLen, // out
              &bk_expr,  // out
              doKeyEncodeOpt,
              firstKeyColOffset,
              doEquiKeyPredOpt);
              
          if (&endKeyPred)
             generateKeyExpr(keyColumns,
                 endKeyPred,
                 work_atp,
                 key_atp_index,
                 dataConversionErrorFlag,
                 tf,
                 keyLen, // out -- should be the same as above
                 &ek_expr,  // out
                 doKeyEncodeOpt,
                 firstKeyColOffset,
                 doEquiKeyPredOpt);
              
          if (reverseScan)
            {
              // reverse scan - swap the begin and end key predicates
              
              // Note: evidently, the Optimizer has already switched
              // the key predicates in this case, so what we are
              // really doing is switching them back.
              
              ex_expr *temp = bk_expr;
              bk_expr = ek_expr;
              ek_expr = temp;
            }
          if (searchKey)
            {
              generateExclusionExpr(searchKey->getBeginKeyExclusionExpr(),
                  work_atp,
                  exclude_flag_atp_index,
                  &bk_excluded_expr); // out
              
              bkey_excluded = (short) searchKey->isBeginKeyExclusive(); 
              
              generateExclusionExpr(searchKey->getEndKeyExclusionExpr(),
                  work_atp,
                  exclude_flag_atp_index,
                  &ek_excluded_expr); // out
              
              ekey_excluded = (short) searchKey->isEndKeyExclusive(); 

              if (reverseScan)
                {
                  NABoolean x = bkey_excluded;
                  bkey_excluded = ekey_excluded;
#pragma nowarn(1506)   // warning elimination 
                  ekey_excluded = x;
#pragma warn(1506)  // warning elimination 

                  ex_expr* temp = bk_excluded_expr;
                  bk_excluded_expr = ek_excluded_expr;
                  bk_excluded_expr = temp;
                }
            } // if searchKey
          else if (useTheHorribleKludge)
            {
              generateExclusionExpr(beginKeyExclusionExpr,
                    work_atp,
                    exclude_flag_atp_index,
                    &bk_excluded_expr); // out
              
              generateExclusionExpr(endKeyExclusionExpr,
                    work_atp,
                    exclude_flag_atp_index,
                    &ek_excluded_expr); // out
              
              // note that the old PartitionAccess::codeGen() code didn't
              // set values for bkey_excluded and ekey_excluded, so the
              // safest choice is to choose inclusion, i.e. let the flags
              // retain their initial value of 0.
            }
          
          // Build key info
          if (keytag > 0)
            keyLen += sizeof(short);

          if ((unique_key_expr == NULL) ||
              (NOT generator->genLeanExpr()))
            {
              // the work cri desc is used to build key values (entry 2) and
              // to compute the exclusion flag (entry 3) to monitor for data
              // conversion errors (entry 4) and to compute values on a column
              // basis (entry 5 - Mdam only)
              ex_cri_desc * work_cri_desc 
                        = new(space) ex_cri_desc(6, space);
              
              *keyInfo = new(space) keySingleSubsetGen(
                   keyLen,
                   work_cri_desc,
                   key_atp_index,
                   exclude_flag_atp_index,
                   data_conv_error_atp_index,
                   bk_expr,
                   ek_expr,
                   bk_excluded_expr,
                   ek_excluded_expr,
                   // static exclude flags (if exprs are NULL)
                   bkey_excluded,
                   ekey_excluded); 
              if (unique_key_expr)
                *unique_key_expr = NULL;
            }
          else
            {
              if (keyInfo)
                *keyInfo = NULL;
              *unique_key_expr = (ex_expr_lean*)bk_expr;
              *uniqueKeyLen = keyLen;
            }
        }
    }  // end of non-mdam case
  else // Mdam case
    {
      // the work cri desc is used to build key values (entry 2) and
      // to compute the exclusion flag (entry 3) to monitor for data
      // conversion errors (entry 4) and to compute values on a column
      // basis (entry 5 - Mdam only, and entry 6 - Mdam only, and only
      // for MDAM_BETWEEN predtype)
      ex_cri_desc * work_cri_desc 
            = new(space) ex_cri_desc(7, space);

      // compute the format of the key buffer -- We need this
      // so that Mdam will know, for each column, where in the buffer
      // to move a value and how many bytes that value takes.  The
      // next few lines of code result in this information being stored
      // in the attrs array.

      // Some words on the technique:  We create expressions whose
      // result datatype matches the key buffer datatypes for each key
      // column.  Then we use the datatypes of these expressions to
      // compute buffer format.  The expressions themselves are not
      // used any further; they do not result in compiled expressions
      // in the plan.  At run time we use string moves to move key
      // values instead.

 
      const CollIndex keyCount = listOfKeyColumns.entries();
      CollIndex i;

      // assert at least one column
      GenAssert(keyCount > 0,"MDAM:  at least one key column required.");

      Attributes ** attrs = new(generator->wHeap()) Attributes * [keyCount];
      
      for (i = 0; i < keyCount; i++)
        {
          ItemExpr * col_node =
              listOfKeyColumns[i].getItemExpr(); 
          ItemExpr *enode = col_node;

          if ((tf == ExpTupleDesc::SQLMX_KEY_FORMAT) &&
              (enode->getValueId().getType().getVarLenHdrSize() > 0))
            {
              // varchar keys in SQL/MP tables are converted to
              // fixed length chars in key buffers

              const CharType& char_type =
                          (CharType&)(enode->getValueId().getType());

              if (!CollationInfo::isSystemCollation(char_type.getCollation()))
                {
                  enode = new(generator->wHeap()) 
                             Cast(enode, 
                                   (new (generator->wHeap())
                                          SQLChar( CharLenInfo(char_type.getStrCharLimit(),
                                                   char_type.getDataStorageSize()),
                                          char_type.supportsSQLnull(),
                                          FALSE, FALSE, FALSE,
                                          char_type.getCharSet(),
                                          char_type.getCollation(),
                                          char_type.getCoercibility())));
                }
            }

          NABoolean desc_flag;

          if (keyColumns.isAscending(i))
            desc_flag = reverseScan;
          else
            desc_flag = !reverseScan;

#pragma nowarn(1506)   // warning elimination 
          enode = new(generator->wHeap()) CompEncode(enode,desc_flag); 
#pragma warn(1506)  // warning elimination 
          enode->bindNode(generator->getBindWA());

          attrs[i] = 
            (generator->
             addMapInfoToThis(keyBufferPartMapTable, enode->getValueId(), 0))->getAttr();
        }  // for, over keyCount

      // Compute offsets, lengths, etc. and assign them to the right
      // atp and atp index

      processAttributes((ULng32)keyCount,
                        attrs, tf,
                        keyLen,
                        work_atp, key_atp_index);

      // Now we have key column offsets and lengths stored in attrs.
 
      // Next, for each column, generate expressions to compute hi,
      // lo, non-null hi and non-null lo values, and create
      // MdamColumnGen structures.

      // Notes: In the Mdam network itself, all key values are
      // encoded.  Hence, we generate CompEncode nodes in all of the
      // expressions, regardless of tuple format.  In the Simulator
      // case, we must at run-time decode the encoded values when
      // moving them to the key buffer.  $$$ We need an expression to
      // do this.  This decoding work has not yet been done, so the
      // simulator only works correctly for columns that happen to be
      // correctly aligned and whose encoding function does not change
      // the value. $$$

      MdamColumnGen * first = 0;
      MdamColumnGen * last = 0;
      LIST(NAType *) keyTypeList(generator->wHeap());//to keep the type of the keys for later

      for (i = 0; i < keyCount; i++)
        {
          // generate expressions to compute hi, lo, non-null hi, non-null lo
          NAType * targetType = (keyColumns[i]->getType())->newCopy(generator->wHeap());

          // Genesis case 10-971031-9814 fix: desc_flag must take into account
          // both the ASC/DESC attribute of the key column and the reverseScan
          // attribute. Before this fix, it only took into account the first of
          // these.
          NABoolean desc_flag;

          if (keyColumns.isAscending(i))
            desc_flag = reverseScan;
          else
            desc_flag = !reverseScan;
          // End Genesis case 10-971031-9814 fix.

          if ((tf == ExpTupleDesc::SQLMX_KEY_FORMAT) &&
              (targetType->getVarLenHdrSize() > 0))
            {

// 5/9/98: add support for VARNCHAR
              const CharType* char_type = (CharType*)(targetType);

              if (!CollationInfo::isSystemCollation(char_type->getCollation()))
                {
                  targetType = new(generator->wHeap()) 
                                      SQLChar( CharLenInfo(char_type->getStrCharLimit(),
                                                           char_type->getDataStorageSize()),
                                      char_type -> supportsSQLnull(),
                                      FALSE, FALSE, FALSE,
                                      char_type -> getCharSet(),
                                      char_type -> getCollation(),
                                      char_type -> getCoercibility());
/*
                  targetType->getNominalSize(),
                  targetType->supportsSQLnull()
*/
                }
            }

          keyTypeList.insert(targetType);  // save in ith position for later
  
          // don't need to make copy of targetType in next call
          ItemExpr * lo = new(generator->wHeap()) ConstValue(targetType, 
                                !desc_flag, 
                                TRUE /* allow NULL */);
#pragma nowarn(1506)   // warning elimination 
          lo = new(generator->wHeap()) CompEncode(lo,desc_flag); 
#pragma warn(1506)  // warning elimination 
          lo->bindNode(generator->getBindWA());

          ValueIdList loList;
          loList.insert(lo->getValueId());

          ex_expr *loExpr = 0;
          ULng32 dataLen = 0;

          generateContiguousMoveExpr(loList,
                   0, // don't add convert nodes
                   work_atp,
                   key_column_atp_index,
                   tf,
                   dataLen,
                   &loExpr);

          ItemExpr * hi = new(generator->wHeap()) ConstValue(targetType->newCopy(generator->wHeap()),
                                desc_flag,
                                TRUE /* allow NULL */);
#pragma nowarn(1506)   // warning elimination 
          hi = new(generator->wHeap()) CompEncode(hi,desc_flag);
#pragma warn(1506)  // warning elimination 
          hi->bindNode(generator->getBindWA());

          ValueIdList hiList;
          hiList.insert(hi->getValueId());

          ex_expr *hiExpr = 0;
          
          generateContiguousMoveExpr(hiList,
                   0, // don't add convert nodes
                   work_atp,
                   key_column_atp_index,
                   tf,
                   dataLen,
                   &hiExpr);

          ex_expr *nonNullLoExpr = loExpr;
          ex_expr *nonNullHiExpr = hiExpr;

          if (targetType->supportsSQLnull())
            {
              if (desc_flag)
                {
                  ItemExpr * nonNullLo = new(generator->wHeap())
                    ConstValue(targetType->newCopy(generator->wHeap()),
                               !desc_flag, 
                               FALSE /* don't allow NULL */);
      #pragma nowarn(1506)   // warning elimination 
                  nonNullLo = new(generator->wHeap()) CompEncode(nonNullLo,desc_flag); 
      #pragma warn(1506)  // warning elimination 
                  nonNullLo->bindNode(generator->getBindWA());

                  ValueIdList nonNullLoList;
                  nonNullLoList.insert(nonNullLo->getValueId());
                  nonNullLoExpr = 0;  // so we will get an expression back

                  generateContiguousMoveExpr(nonNullLoList,
                           0, // don't add convert nodes
                           work_atp,
                           key_column_atp_index,
                           tf,
                           dataLen,
                           &nonNullLoExpr);
                }
              else
                {
                  ItemExpr * nonNullHi = new(generator->wHeap())
                    ConstValue(targetType->newCopy(generator->wHeap()),
                         desc_flag, 
                         FALSE /* don't allow NULL */);
#pragma nowarn(1506)   // warning elimination 
                  nonNullHi = new(generator->wHeap()) CompEncode(nonNullHi,desc_flag); 
#pragma warn(1506)  // warning elimination 
                  nonNullHi->bindNode(generator->getBindWA());
                  
                  ValueIdList nonNullHiList;
                  nonNullHiList.insert(nonNullHi->getValueId());
                  nonNullHiExpr = 0;  // so we will get an expression back
                  
                  generateContiguousMoveExpr(nonNullHiList,
                           0, // don't add convert nodes
                           work_atp,
                           key_column_atp_index,
                           tf,
                           dataLen,
                           &nonNullHiExpr);
                }
            }

          NABoolean useSparseProbes = mdamKeyPtr->isColumnSparse(i); 
          
          // calculate offset to the beginning of the column value
          // (including the null indicator and the varchar length
          // indicator if present)

          ULng32 column_offset = attrs[i]->getOffset();

          if (attrs[i]->getNullFlag())
            column_offset = attrs[i]->getNullIndOffset();
          else if (attrs[i]->getVCIndicatorLength() > 0)
            column_offset = attrs[i]->getVCLenIndOffset();

          last = new(space) MdamColumnGen(last,
                  dataLen,
                  column_offset,
                  useSparseProbes,
                  loExpr,
                  hiExpr,
                  nonNullLoExpr,
                  nonNullHiExpr);
          if (first == 0)
            first = last;
        }  // for over keyCount

      // generate MdamPred's and attach to MdamColumnGen's

      const ColumnOrderListPtrArray &columnOrderListPtrArray =
           mdamKeyPtr->getColumnOrderListPtrArray();

#ifdef _DEBUG
      // Debug print stataments below depend on this
      // variable:
      char *ev = getenv("MDAM_PRINT");
      const NABoolean mdamPrintOn = (ev != NULL AND strcmp(ev,"ON")==0);
#endif

#ifdef _DEBUG
      if (mdamPrintOn)
        {
          fprintf(stdout, "\n\n***Generating the MDAM key for table with index"
                  " columns: ");
          listOfKeyColumns.display();
        }
#endif

      for (CollIndex n = 0; n < columnOrderListPtrArray.entries(); n++)
        {
          // get the list of key predicates associated with the n disjunct:
          const ColumnOrderList &columnOrderList = *columnOrderListPtrArray[n];

#ifdef _DEBUG
          if (mdamPrintOn)
            {
              fprintf(stdout,"\nDisjunct[%d]:----------------\n",n);
              columnOrderList.print();
            }
#endif
          MdamColumnGen * cc = first;

          CMPASSERT(keyCount == columnOrderList.entries());
          const ValueIdSet *predsPtr = NULL;
          for (i = 0; i < keyCount; i++)
            {
#ifdef _DEBUG
              if (mdamPrintOn)
                {
                  fprintf(stdout, "Column(%d) using: ", i);
                  if ( mdamKeyPtr->isColumnSparse(i) )
                    fprintf(stdout,"SPARSE probes\n");
                  else
                    fprintf(stdout, "DENSE probes\n");
                }
#endif
              // get predicates for column order i:
              predsPtr = columnOrderList[i];

              NAType * keyType = keyTypeList[i];

              NABoolean descending;

              if (keyColumns.isAscending(i))
                descending = reverseScan;
              else
                descending = !reverseScan;

              ValueId keyColumn = listOfKeyColumns[i];

              MdamCodeGenHelper mdamHelper(
                   n,
                   keyType,
                   descending,
                   work_atp,
                   key_column_atp_index,
                   tf,
                   dataConversionErrorFlag,
                   keyColumn);

              MdamPred * lastPred = cc->getLastPred();

              if (predsPtr != NULL)
                {
                  for (ValueId predId = predsPtr->init(); 
                       predsPtr->next(predId); predsPtr->advance(predId))
                    {
                      MdamPred * head = 0;  // head of generated MdamPred's
                      MdamPred * tail = 0;

                      ItemExpr * orGroup = predId.getItemExpr();

                      orGroup->mdamPredGen(generator,&head,&tail,mdamHelper,NULL);

                      if (lastPred)
                        {
                          if ( CmpCommon::getDefault(RANGESPEC_TRANSFORMATION) == DF_ON )
                            {
                              MdamPred* curr = lastPred;
                              while(curr->getNext() != NULL)
                                curr=curr->getNext();
                              curr->setNext(head);
                            }
                          else
                            lastPred->setNext(head);
                        }
                      cc->setLastPred(tail);
                      lastPred = tail;  //@ZXmdam if 1st pred has head != tail, head is lost
                    } // for over preds
                } // if (predsPtr != NULL)
              cc = cc->getNext();
            } // for every order...
        } // for every column order list in the array (of disjuncts)

      // build the Mdam key info
      if (keytag > 0)
        keyLen += sizeof(short);
      *keyInfo = new(space) keyMdamGen(keyLen,
                                       work_cri_desc,
                                       key_atp_index,
                                       exclude_flag_atp_index,
                                       data_conv_error_atp_index,
                                       key_column_atp_index,
                                       first,
                                       last,
                                       reverseScan,
                                       generator->wHeap());

    }  // end of mdam case

  if (*keyInfo)
    (*keyInfo)->setKeytag(keytag);

  // reset map table to forget about the key object's work Atp
  
  // aside: this logic is more bloody than it should be because the
  // map table implementation doesn't accurately reflect the map table
  // abstraction
  
  generator->removeAll(keyBufferPartMapTable); // deletes anything that might have been
  // added after keyBufferPartMapTable (at
  // this writing we don't expect there to
  // be anything, but we want to be safe)
  // at this point keyBufferPartMapTable should be the last map table in the
  // global map table chain
  generator->removeLast();  // unlinks keyBufferPartMapTable and deletes it
  
  return 0;
};