C++ Join::synthLogProp方法代码示例

void MultiJoin::synthLogPropWithMJReuse(NormWA * normWAPtr)
{
  // Check to see whether this GA has already been associated
  // with a logExpr for synthesis.  If so, no need to resynthesize
  // for this equivalent log. expression.
  if (getGroupAttr()->existsLogExprForSynthesis())
  {
    Join * joinExprForSynth = 
      (Join *) getGroupAttr()->getLogExprForSynthesis();
      
    if(joinExprForSynth->isJoinFromMJSynthLogProp())
      return;
  }

  NABoolean reUseMJ = TRUE;

  CMPASSERT ( (jbbSubset_.getGB() == NULL_CA_ID));

  const CANodeIdSet & jbbcs = jbbSubset_.getJBBCs();

  // Instead of always picking the first JBBC as the right child
  // pick the one with minimum JBBC connections. This will avoid
  // all unnecessary crossproducts

  CANodeId jbbcRight;

  jbbcRight = jbbcs.getJBBCwithMinConnectionsToThisJBBSubset();

  CANodeIdSet right(jbbcRight);
  CANodeIdSet left(jbbcs);
  left -= jbbcRight;

  Join* join = splitSubset(*(left.jbbcsToJBBSubset()),
                             *(right.jbbcsToJBBSubset()),
                           reUseMJ);

  //if the left is a MultiJoin, synthesize it using reUse
  //this has to be done before join->synthLogProp to avoid
  //calling MultiJoin::synthLogProp on the left MultiJoin
  //because that does not reUse
  if(left.entries() > 1)
  {
    RelExpr * leftRelExpr = join->child(0)->castToRelExpr();
    if(leftRelExpr &&
       leftRelExpr->getOperator() == REL_MULTI_JOIN)
      ((MultiJoin *) leftRelExpr)->synthLogPropWithMJReuse(normWAPtr);
  }

  join->synthLogProp(normWAPtr);

  join->setJoinFromMJSynthLogProp();

  getGroupAttr()->setLogExprForSynthesis(join);

  jbbSubset_.setSubsetMJ(this);

  CMPASSERT ( getGroupAttr()->getNumJoinedTables() >= getArity());
}

void MultiJoin::synthLogProp(NormWA * normWAPtr)
{
  // Check to see whether this GA has already been associated
  // with a logExpr for synthesis.  If so, no need to resynthesize
  // for this equivalent log. expression.
  if (getGroupAttr()->existsLogExprForSynthesis()) return;

  CMPASSERT ( (jbbSubset_.getGB() == NULL_CA_ID));

  const CANodeIdSet & jbbcs = jbbSubset_.getJBBCs();

  // Instead of always picking the first JBBC as the right child
  // pick the one with minimum JBBC connections. This will avoid
  // all unnecessary crossproducts

  CANodeId jbbcRight;

  jbbcRight = jbbcs.getJBBCwithMinConnectionsToThisJBBSubset();

  CANodeIdSet right(jbbcRight);
  CANodeIdSet left(jbbcs);
  left -= jbbcRight;

  Join* join = splitSubset(*(left.jbbcsToJBBSubset()),
                             *(right.jbbcsToJBBSubset()));

  join->synthLogProp(normWAPtr);

  getGroupAttr()->setLogExprForSynthesis(join);

  join->setJoinFromMJSynthLogProp();

  jbbSubset_.setSubsetMJ(this);
  
  CASortedList * synthLogPropPath =        
    new (CmpCommon::statementHeap()) 
    CASortedList(CmpCommon::statementHeap(), jbbcs.entries());
      
  synthLogPropPath->insert((*(left.jbbcsToJBBSubset()->getSynthLogPropPath())));
  synthLogPropPath->insert(right.getFirst());
  jbbSubset_.setSynthLogPropPath(synthLogPropPath);

  CMPASSERT ( getGroupAttr()->getNumJoinedTables() >= getArity());
}

//.........这里部分代码省略.........

  // in an iteration this is the parent join
  // e.g. when we are create JOIN3, this will
  // be JOIN2
  Join * parentJoin = NULL;

#ifdef _DEBUG
  if ( CmpCommon::getDefault( NSK_DBG ) == DF_ON  &&
       CmpCommon::getDefault( NSK_DBG_MJRULES_TRACKING ) == DF_ON )
  {
// LCOV_EXCL_START - dpm
    CURRCONTEXT_OPTDEBUG->stream() << "Following is left deep join sequence: " << endl;
    CURRCONTEXT_OPTDEBUG->stream() << endl;
// LCOV_EXCL_STOP
  }
#endif

  UInt32 numJoinChildren = leftDeepJoinSequence->entries();

  CANodeId currentTable = NULL_CA_ID;

  for (UInt32 i = 0; i < (numJoinChildren-1); i++)
  {
    //create JBBSubset representing a comprising component of the
    //leftDeepJoinSequence.
    JBBSubset * joinRightChild = ((*leftDeepJoinSequence)[i]).computeJBBSubset();

    MJJoinDirective * joinDirective = (*joinDirectives)[i];

    //remove all tables that will become right side of join
    childSet.remove((*leftDeepJoinSequence)[i]);

#ifdef _DEBUG
    //print the right child of the current join
    if ( CmpCommon::getDefault( NSK_DBG ) == DF_ON  &&
       CmpCommon::getDefault( NSK_DBG_MJRULES_TRACKING ) == DF_ON )
    {
      CURRCONTEXT_OPTDEBUG->stream() << ((*leftDeepJoinSequence)[i]).getText() << endl; // LCOV_EXCL_LINE - dpm
    }
#endif
    //Get JBBSubset for left side of join
    JBBSubset * joinLeftChild = childSet.computeJBBSubset();

    //create the join by doing a split of the multi-join
    currentJoin = currentMJoin->splitSubset(*joinLeftChild, *joinRightChild, reUseMultiJoins);

    joinDirective->setupJoin(currentJoin);

    if ( CmpCommon::getDefault(COMP_BOOL_120) == DF_OFF)
      currentJoin->updatePotential(-3);

    // if this is the first iteration
    // set the result to be the top join
    if (i == 0)
      result = currentJoin;

    //set the current multi-join to the left child of the
    //join just created
    //change getChild to child().getPointer
    currentMJoin = (MultiJoin*) currentJoin->getChild(0);

    //if there was a parent join, set the left child to
    //point to the new join we just created i.e. currentJoin.
    if (parentJoin)
      parentJoin->setChild(0,currentJoin);

    //set currentJoin to be the parent for the next iteration
    parentJoin = currentJoin;

  }

#ifdef _DEBUG
  //print the left most child
  if ( CmpCommon::getDefault( NSK_DBG ) == DF_ON  &&
       CmpCommon::getDefault( NSK_DBG_MJRULES_TRACKING ) == DF_ON )
  {
// LCOV_EXCL_START  - dpm
    CURRCONTEXT_OPTDEBUG->stream() << ((*leftDeepJoinSequence)[(numJoinChildren-1)]).getText() << endl;
    CURRCONTEXT_OPTDEBUG->stream() << endl;
// LCOV_EXCL_STOP
  }
#endif

  // end - construct the join tree

  // synth the join
  result->synthLogProp();

  //if the right child of the top-most join is a multi-Join,
  //synthesize_it
  if(result->child(1))
    if(result->child(1)->getOperatorType()==REL_MULTI_JOIN)
      result->child(1)->synthLogProp();

  // synth the left child too
  result->child(0)->synthLogProp();

  return result;

} // MultiJoin::createLeftLinearJoinTree()

//.........这里部分代码省略.........
        jbbSubsetExpr = getExprForCANodeId(jbbSubset.getFirst(), inputEstLogProp);
        inputEstLogProp->setCacheableFlag(FALSE);
      }
      else
        jbbSubsetExpr = getExprForCANodeId(jbbSubset.getFirst(), inputEstLogProp);
    else
    {
      CCMPASSERT("No Subset expression, need at least one entry in set");
    }


  RelExpr * leftChildExpr = jbbSubsetExpr;
  RelExpr * rightChildExpr = jbbcExpr;
  
  GroupAttributes * galeft = jbbSubsetExpr->getGroupAttr();
  GroupAttributes * garight = jbbcExpr->getGroupAttr();
  
  // xxx

  JBBC * jbbc = jbbcId.getNodeAnalysis()->getJBBC();
  Join * jbbcParentJoin = jbbc->getOriginalParentJoin();
  ValueIdSet leftOuterJoinFilterPreds;


  Join * joinExpr = NULL;
  
  if(jbbcParentJoin)
  {
      if(jbbcParentJoin->isSemiJoin())
        joinExpr = new STMTHEAP Join(leftChildExpr, rightChildExpr, REL_SEMIJOIN, NULL);

      if(jbbcParentJoin->isAntiSemiJoin())
        joinExpr = new STMTHEAP Join(leftChildExpr, rightChildExpr, REL_ANTI_SEMIJOIN, NULL);

      if(jbbcParentJoin->isLeftJoin())
      {
        joinExpr = new STMTHEAP Join(leftChildExpr, rightChildExpr, REL_LEFT_JOIN, NULL);
        leftOuterJoinFilterPreds += jbbc->getLeftJoinFilterPreds();
      }

      if(joinExpr)
      {
        joinExpr->setJoinPred(jbbc->getPredsWithPredecessors());

        joinExpr->nullInstantiatedOutput().insert(jbbc->nullInstantiatedOutput());
      }
  }

  if(!joinExpr)
  {
    // now form a JoinExpr with these left and right children.
    joinExpr = new STMTHEAP Join(leftChildExpr, rightChildExpr, REL_JOIN, NULL);
  }

  ValueIdSet selPredsAndLOJFilter = leftOuterJoinFilterPreds;
  selPredsAndLOJFilter += (*joinPreds);
  joinExpr->setSelectionPredicates(selPredsAndLOJFilter);

  // set groupAttr of this Join expression
  GroupAttributes * gaJoin = new STMTHEAP GroupAttributes();

  // set required outputs of Join as sum of characteristic
  // outputs of the left and the right children
  ValueIdSet requiredOutputs;

  requiredOutputs.addSet(getPotentialOutputs(jbbSubset));

  requiredOutputs.addSet(getPotentialOutputs(jbbcId));

  gaJoin->setCharacteristicOutputs(requiredOutputs);

  // set JBBSubset for this group, if all estLogProps are cacheable.
  // Else JBBSubset is NULL

  CANodeIdSet combinedSet = jbbSubset;
  combinedSet += jbbcId;
  
  if (cacheable)
    gaJoin->getGroupAnalysis()->setLocalJBBView(combinedSet.jbbcsToJBBSubset());

  gaJoin->setMinChildEstRowCount(MINOF(garight->getMinChildEstRowCount(), galeft->getMinChildEstRowCount() ) );

  // if there are some probes coming into the join
  // then join type = tsj.
  if ((inputEstLogProp->getResultCardinality() > 1) ||
      (inputEstLogProp->getColStats().entries() > 1))
  {
    if (cacheable)
    {
      CANodeIdSet inputNodeSet =  *(inputEstLogProp->getNodeSet());
      gaJoin->setCharacteristicInputs(getPotentialOutputs(inputNodeSet));
    }
  }

  joinExpr->setGroupAttr(gaJoin);
  gaJoin->setLogExprForSynthesis(joinExpr);
  joinExpr->synthLogProp();
  inputEstLogProp->setCacheableFlag(origInputIsCacheable);
  return joinExpr;
} // AppliedStatMan::formJoinExprForJoinOnJBBC