EstLogPropSharedPtr AppliedStatMan::synthesizeLogProp(
const CANodeIdSet * nodeSet,
EstLogPropSharedPtr &inLP)
{
EstLogPropSharedPtr outputEstLogProp;
CANodeIdSet combinedNodeSetWithInput = *nodeSet;
if (inLP->isCacheable())
{
CANodeIdSet * inNodeSet = inLP->getNodeSet();
// if inLP are cacheable these should have a nodeSet attached
// if not, assert in debug mode. In release mode, set the properties
// as not cacheable. These will then be looked into group attr cache
if (inNodeSet == NULL)
{
CCMPASSERT(inNodeSet != NULL);
inLP->setCacheableFlag(FALSE);
}
else
{
// check ASM cache for the estLogProps of nodeSet for the given
// inLP
combinedNodeSetWithInput.insert(*inNodeSet);
if ((outputEstLogProp =\
getCachedStatistics(&combinedNodeSetWithInput)) != NULL)
return outputEstLogProp;
}
}
if(nodeSet->entries() == 1)
return getStatsForCANodeId(nodeSet->getFirst(), inLP);
JBBSubset * jbbSubset = nodeSet->jbbcsToJBBSubset();
Join * preferredJoin = jbbSubset->getPreferredJoin();
//CMPASSERT(preferredJoin->isJoinFromMJSynthLogProp());
outputEstLogProp = preferredJoin->getGroupAttr()->outputLogProp(inLP);
return outputEstLogProp;
} // AppliedStatMan::synthesizeLogProp
// LCOV_EXCL_START
// Used for other RelExpr but not MultiJoin
void MultiJoin::synthEstLogProp(const EstLogPropSharedPtr& inputEstLogProp)
{
CMPASSERT(inputEstLogProp->getNodeSet());
Join * preferredJoin = jbbSubset_.getPreferredJoin();
CMPASSERT(preferredJoin->isJoinFromMJSynthLogProp());
EstLogPropSharedPtr myEstLogProp =
preferredJoin->getGroupAttr()->outputLogProp(inputEstLogProp);
getGroupAttr()->addInputOutputLogProp (inputEstLogProp, myEstLogProp, NULL);
} // MultiJoin::synthEstLogProp
NABoolean AppliedStatMan::insertCachePredStatEntry(
const CANodeIdSet & jbbcNodeSet,
const EstLogPropSharedPtr& estLogProp)
{
CANodeIdSet * tableSet = new (STMTHEAP) CANodeIdSet (jbbcNodeSet);
// FIXME!!! Must properly create cacheASM_
CANodeIdSet * result = cacheASM_->
insert(tableSet, estLogProp.get());
if (result == NULL)
return FALSE; // insert failed.
else
return TRUE; // insert successful
} // AppliedStatMan::insertCachePredStatEntry
EstLogPropSharedPtr AppliedStatMan::joinJBBChildren(
const CANodeIdSet & leftChildren,
const CANodeIdSet & rightChildren,
EstLogPropSharedPtr & inLP)
{
EstLogPropSharedPtr inputLP = inLP;
EstLogPropSharedPtr outputEstLogProp;
if(inputLP == (*GLOBAL_EMPTY_INPUT_LOGPROP))
inputLP = leftChildren.getJBBInput();
// Because there exist a nodeSet for the left, right and the outer
// child, hence these properties are cacheable. Check to see if the
// outputEstLogProp of the join for the given inLP exist in the cache
CANodeIdSet combinedNodeSet = leftChildren;
combinedNodeSet.insert(rightChildren);
CANodeIdSet * inNodeSet = NULL;
if (inputLP->isCacheable())
{
inNodeSet = inputLP->getNodeSet();
CANodeIdSet combinedWithInputNodeSet = combinedNodeSet;
combinedWithInputNodeSet.insert(*inNodeSet);
outputEstLogProp = getCachedStatistics(&combinedWithInputNodeSet);
}
if(outputEstLogProp == NULL)
outputEstLogProp = synthesizeLogProp(&combinedNodeSet, inputLP);
return outputEstLogProp;
} // AppliedStatMan::joinJBBChildren
COMPARE_RESULT EstLogProp::compareEstLogProp (const EstLogPropSharedPtr &other) const
{
if (this == other.get())
return SAME;
// First thing that we may want to compare is the CANodeSets of the EstLogProp
// if these are NOT NULL
// This would work if Query Analizer created nodeSet_ for this and other
if ((nodeSet_ != NULL) && (other->nodeSet_ != NULL))
{
if ((*nodeSet_) == (*(other->nodeSet_)))
return SAME;
else
return INCOMPATIBLE;
}
// This is the old logic after removing heuristic returning SAME for close
// EstLogProp like resultCardinality_/other->resultCardinality in [0.8,1.2]
// That heuristics was incompatible with Cascades assumption that in the case
// when pruning is on we cannot have 2 different context for optimization
// if their comparison returns SAME.
if ( resultCardinality_ == other->resultCardinality_ AND
( // Check for the case where we have two "empty" input logical properties.
( columnStats_.entries() == 0 AND other->columnStats_.entries() == 0)
OR
( columnStats_ == other->columnStats_ AND
unresolvedPreds_ == other->unresolvedPreds_ AND
inputForSemiTSJ_ == other->inputForSemiTSJ_ )
)
)
return SAME;
return INCOMPATIBLE;
}
// ---------------------------------------------------------------------
// Utility Routine: pickOutputs
//
// From the given ColStatDescList, populate columnStats_ with column
// descriptors that are useful based on the characteristic outputs for
// the group.
//
// Always include in the output the current histograms of the input data,
// and, if the histogram is contained in the required output list, then
// this is a useful histogram and will also be output.
//
// ---------------------------------------------------------------------
void EstLogProp::pickOutputs( ColStatDescList & columnStats,
const EstLogPropSharedPtr& inputEstLogProp,
const ValueIdSet specifiedOutputs,
const ValueIdSet predSet)
{
const ColStatDescList & outerColStatsList = inputEstLogProp->getColStats();
ValueIdSet colsRequiringHistograms = specifiedOutputs;
// (i) see if the selection predicates contain any constant value or a
// constant expression
// (ii) check if there are any columns of this table being joined to some other
// columns, which do not appear as characteristics outputs. There should be
// histograms available for these columns, as these might be needed later.
// This problem was seen for temporary tables created as normal_tables by the
// triggers.
colsRequiringHistograms.addSet(predSet.getColumnsForHistogram());
colStats().setMCSkewedValueLists(columnStats.getMCSkewedValueLists()) ;
NABoolean colStatDescAdded = FALSE;
for (CollIndex i=0; i < columnStats.entries(); i++)
{
// we probably don't need 'em all, but this is the easiest way to
// grab all of the multi-column uec information we'll need later
colStats().insertIntoUecList (columnStats.getUecList()) ;
colStats().setScanRowCountWithoutHint(columnStats.getScanRowCountWithoutHint());
NABoolean found = FALSE;
// Note: The following inserts into a ColStatDescList should not
// have to be deep copies. From this point on, ColStatDescs that
// describe the output of the calling operator are read-only.
ColStatDescSharedPtr colStatDesc = columnStats[i];
// the value-id we're looking for
const ValueId columnId = colStatDesc->getVEGColumn() ;
for (CollIndex j=0 ; j < outerColStatsList.entries() ; j++)
{
if (columnId == outerColStatsList[j]->getVEGColumn() OR
(CmpCommon::context()->showQueryStats()))
{
colStats().insert(colStatDesc) ;
found = TRUE;
if(!colStatDescAdded)
colStatDescAdded = TRUE;
break ; // jump to next ColStatDesc
}
}
// OK, the valueid doesn't match directly -- but there are still a
// couple of things to check in order to verify whether or not we're
// interested in keeping the i'th ColStatDesc ...
ValueId throwaway ; // used by the second clause below
if ( NOT found AND
(columnId != NULL_VALUE_ID) AND
(colsRequiringHistograms.contains (columnId) OR
colsRequiringHistograms.referencesTheGivenValue (columnId, throwaway) OR
columnId.isInvolvedInJoinAndConst() OR
CmpCommon::context()->showQueryStats() )
)
{
colStats().insert(colStatDesc);
found = TRUE;
if(!colStatDescAdded)
colStatDescAdded = TRUE;
}
if (CURRSTMT_OPTDEFAULTS->incorporateSkewInCosting())
{
// if the column is referenced for histogram, but is
// not needed beyond this time , then we shall save its
// max freq, which might be used later in costing if this
// column is a part of the partitioning key
ColStatsSharedPtr stat = colStatDesc->getColStats();
if (!(stat->isVirtualColForHist() ) && NOT found &&
!(stat->isOrigFakeHist() ) )
{
const ValueId col = colStatDesc->getColumn();
ColAnalysis * colAnalysis = col.colAnalysis();
if (colAnalysis)
{
NAColumn * column = stat->getStatColumns()[0];
if (column->isReferencedForHistogram())
{
CostScalar maxFreq = columnStats.getMaxFreq(columnId);
colAnalysis->setMaxFreq(maxFreq);
colAnalysis->setFinalUec(stat->getTotalUec());
colAnalysis->setFinalRC(stat->getRowcount());
}
}
}
}
} // for columnStats.entries()
if(!colStatDescAdded && columnStats.entries() > 0)
colStats().insert(columnStats[0]) ;
} // pickOutputs
CostScalar AppliedStatMan::computeJoinReduction(
const CANodeIdSet & leftChildren,
const CANodeIdSet & rightChildren)
{
CostScalar result = 0;
// get stats for left
EstLogPropSharedPtr leftCard =
getStatsForCANodeIdSet(leftChildren);
// get stats for right
EstLogPropSharedPtr rightCard =
getStatsForCANodeIdSet(rightChildren);
CANodeIdSet jbbcsJoinedToRight;
CANodeIdSet allPredecessors;
CANodeIdSet allSuccessors;
for( CANodeId rChild = rightChildren.init();
rightChildren.next(rChild);
rightChildren.advance(rChild))
{
JBBC * rChildJBBC = rChild.getNodeAnalysis()->getJBBC();
jbbcsJoinedToRight += rChildJBBC->getJoinedJBBCs();
jbbcsJoinedToRight += rChildJBBC->getPredecessorJBBCs();
allPredecessors += rChildJBBC->getPredecessorJBBCs();
jbbcsJoinedToRight += rChildJBBC->getSuccessorJBBCs();
allSuccessors += rChildJBBC->getSuccessorJBBCs();
}
CANodeIdSet dependencyCausingNodesFromLeft = leftChildren;
dependencyCausingNodesFromLeft.intersectSet(allPredecessors + allSuccessors);
CANodeIdSet leftNodesJoinedToRight = leftChildren;
leftNodesJoinedToRight.intersectSet(jbbcsJoinedToRight);
if(!leftNodesJoinedToRight.entries())
{
result = rightCard->getResultCardinality();
return result;
}
CANodeIdSet leftSetPredecessors;
CANodeIdSet newNodes = leftNodesJoinedToRight;
CANodeIdSet nodesConsidered;
while(newNodes.entries())
{
for( CANodeId lChild = newNodes.init();
newNodes.next(lChild);
newNodes.advance(lChild))
{
JBBC * lChildJBBC = lChild.getNodeAnalysis()->getJBBC();
leftSetPredecessors += lChildJBBC->getPredecessorJBBCs();
nodesConsidered += lChild;
}
leftSetPredecessors.intersectSet(leftChildren);
newNodes = leftSetPredecessors;
newNodes -= nodesConsidered;
}
leftNodesJoinedToRight += leftSetPredecessors;
// for a JBBSubset to be legal it has to have at least one
// independent jbbc i.e. a jbbcs connect via a innerNonSemiNonTsjJoin
// Assumption: leftChildren represents a legal JBBSubset
CANodeIdSet independentJBBCsInLeftNodesJoinedToRight =
QueryAnalysis::Instance()->getInnerNonSemiNonTSJJBBCs();
independentJBBCsInLeftNodesJoinedToRight.intersectSet(leftNodesJoinedToRight);
if(!independentJBBCsInLeftNodesJoinedToRight.entries())
leftNodesJoinedToRight +=
leftChildren.jbbcsToJBBSubset()->
getJBBSubsetAnalysis()->
getLargestIndependentNode();
EstLogPropSharedPtr cardLeftNodesJoinedToRight =
getStatsForCANodeIdSet(leftNodesJoinedToRight);
// All nodes connected via a join
CANodeIdSet connectedNodes(leftNodesJoinedToRight);
connectedNodes += rightChildren;
EstLogPropSharedPtr cardConnectedNodes =
joinJBBChildren(leftNodesJoinedToRight,rightChildren);
result = cardConnectedNodes->getResultCardinality() /
cardLeftNodesJoinedToRight->getResultCardinality();
return result;
}
// LCOV_EXCL_START :cnu
EstLogPropSharedPtr AppliedStatMan::joinEstLogProps (
const EstLogPropSharedPtr& leftEstLogProp,
const EstLogPropSharedPtr& rightEstLogProp,
const EstLogPropSharedPtr& inLP)
{
EstLogPropSharedPtr outputEstLogProp;
NABoolean cacheable = FALSE;
CANodeIdSet * inputNodeSet = inLP->getNodeSet();
// These nodesets could be NULL, if the estLogProps to which they
// belong are not cacheable
CANodeIdSet * leftNodeSet = leftEstLogProp->getNodeSet();
CANodeIdSet * rightNodeSet = rightEstLogProp->getNodeSet();
if ((leftEstLogProp->isCacheable()) &&
(rightEstLogProp->isCacheable()) &&
(inLP->isCacheable()) )
{
CCMPASSERT(leftNodeSet != NULL);
CCMPASSERT(rightNodeSet != NULL);
CCMPASSERT(inputNodeSet != NULL);
if (leftNodeSet && rightNodeSet && inputNodeSet)
{
cacheable = TRUE;
}
}
if (cacheable)
{
// check the ASM cache to see if outputEstLogProp for these
// NodeSets appear for the given inputEstLogProp
CANodeIdSet combineNodeSet = *leftNodeSet;
combineNodeSet.insert(*rightNodeSet);
CANodeIdSet combinedWithInputNodeSet = combineNodeSet;
combinedWithInputNodeSet.insert(*inputNodeSet);
outputEstLogProp = getCachedStatistics(&combinedWithInputNodeSet);
if (outputEstLogProp != NULL)
return outputEstLogProp;
}
JBBSubset * newJBBSubset = NULL;
ValueIdSet setOfPredicates;
if (leftNodeSet && rightNodeSet)
{
// join predicates can be obtained from EstLogProp, only
// if these corresponded to complete set of predicates -
// all local or complete join. Also, we need a
// combinedJBBSubset to set in the fake join expression
// that we will be creating.
newJBBSubset = leftNodeSet->computeJBBSubset();
JBBSubset rightJBBSubset = *(rightNodeSet->computeJBBSubset());
setOfPredicates = newJBBSubset->joinPredsWithOther(rightJBBSubset);
// Since the properties from this group are cacheable, hence the
// group attributes for the new join expression should contain
// the combined JBBsubset of the left and the right children
newJBBSubset->addSubset(rightJBBSubset);
}
// inputEstLogProp would be either empty input estLogProp or from the
// outer child. If cacheable is TRUE, then newJBBsubset should
// contain the combined left and the right JBB subset. But if
// cacheable is FALSE, newJBBsubset should be NULL
Join * joinExpr = formJoinExprWithEstLogProps(
leftEstLogProp,
rightEstLogProp,
inLP,
&setOfPredicates,
cacheable,
newJBBSubset);
// Now do the actual synthesis and cache statistics in the cache
outputEstLogProp = joinExpr->getGroupAttr()->outputLogProp(inLP);
return outputEstLogProp;
}
Join * AppliedStatMan::formJoinExprWithCANodeSets(
const CANodeIdSet & leftNodeSet,
const CANodeIdSet & rightNodeSet,
EstLogPropSharedPtr& inLP,
const ValueIdSet * joinPreds,
const NABoolean cacheable)
{
EstLogPropSharedPtr leftEstLogProp = NULL;
EstLogPropSharedPtr rightEstLogProp = NULL;
CANodeIdSet * inputNodeSet = NULL;
if (inLP->isCacheable())
{
inputNodeSet = inLP->getNodeSet();
// if inLP are cacheable these should have a nodeSet attached
// if it is not for some reason, assert in debug mode. In release
// mode do not look for properties in ASM cache, instead get them
// from group attr cache.
if (inputNodeSet == NULL)
{
CCMPASSERT(inputNodeSet != NULL);
inLP->setCacheableFlag(FALSE);
}
}
CANodeIdSet commonNodeSet = leftNodeSet;
commonNodeSet.intersectSet(rightNodeSet);
// remove CANodeIds which are common to both left and the right children
// from the child, whose estLogProps are not cached. If the estLogProps
// of both children are not cached, then remove it from the child which
// has a larger CANodeIdSet associated with it.
CANodeIdSet tempLeftNodeSet = leftNodeSet;
CANodeIdSet tempRightNodeSet = rightNodeSet;
if (commonNodeSet.entries() > 0)
{
if (lookup(leftNodeSet))
tempRightNodeSet.subtractSet(commonNodeSet);
else
if (lookup(rightNodeSet))
tempLeftNodeSet.subtractSet(commonNodeSet);
else
if (leftNodeSet.entries() > rightNodeSet.entries())
tempLeftNodeSet.subtractSet(commonNodeSet);
else
tempRightNodeSet.subtractSet(commonNodeSet);
}
// get the estLogProps for the left and the right child.
// If these are not in the cache, then synthesize them incrementally
// starting from the left most JBBC in the JBBSubset
if (inputNodeSet)
{
// leftEstLogProp cached?
CANodeIdSet combinedNodeSetWithInput = tempLeftNodeSet;
combinedNodeSetWithInput.insert(*inputNodeSet);
leftEstLogProp = getCachedStatistics(&combinedNodeSetWithInput);
combinedNodeSetWithInput = tempRightNodeSet;
combinedNodeSetWithInput.insert(*inputNodeSet);
rightEstLogProp = getCachedStatistics(&combinedNodeSetWithInput);
}
if (leftEstLogProp == NULL)
leftEstLogProp = synthesizeLogProp(&tempLeftNodeSet, inLP);
// if the estimate logical properties have been computed for non-cacheable
// inLP, then these would not contain nodeSet. But we do need the nodeSet
// to compute potential output values. Hence we shall add this now
if (!leftEstLogProp->getNodeSet())
{
CANodeIdSet * copyLeftNodeSet = new (STMTHEAP) CANodeIdSet (tempLeftNodeSet);
leftEstLogProp->setNodeSet(copyLeftNodeSet);
}
if (rightEstLogProp == NULL)
rightEstLogProp = synthesizeLogProp(&tempRightNodeSet, inLP);
if (!rightEstLogProp->getNodeSet())
{
CANodeIdSet * copyRightNodeSet = new (STMTHEAP) CANodeIdSet (tempRightNodeSet);
rightEstLogProp->setNodeSet(copyRightNodeSet);
}
// Now form the join expressions with these EstLogProp,
// inLP and the joinPred will be same as those for which the
// estLogProp are to be synthesized. Cacheable flag would depend
// on whether left, right and the outer child are caheable, or
// if the join is on all columns or not
// Since the join expression consists of the left and the right
// JBBSubsets, the JBBSubset for this Join expression would be
// the superset of left and right JBBSubset
JBBSubset * combinedSet = leftNodeSet.jbbcsToJBBSubset();
combinedSet->addSubset(*(rightNodeSet.jbbcsToJBBSubset()));
// Now form the join expressions with these EstLogProp,
// inLP and the joinPred will be same as those for which the
// estLogProp are to be synthesized. Cacheable flag would depend
// on whether left, right and the outer child are ccaheable, or
// if the join is on all columns or not
return formJoinExprWithEstLogProps(leftEstLogProp, rightEstLogProp,
inLP, joinPreds, cacheable, combinedSet);
} // AppliedStatMan::formJoinExprWithCANodeSets
EstLogPropSharedPtr AppliedStatMan::getStatsForCANodeId(
CANodeId jbbc,
const EstLogPropSharedPtr &inLP,
const ValueIdSet * predIdSet)
{
EstLogPropSharedPtr inputLP = inLP;
if(inputLP == (*GLOBAL_EMPTY_INPUT_LOGPROP))
inputLP = jbbc.getJBBInput();
EstLogPropSharedPtr outputEstLogProp = NULL;
// 1. Try to find Logical Properties from cache if cacheable.
// The estimate Logical Properties can be cacheable if all local
// predicates are to be applied and if inNodeSet is provided,
// or the inLP are cacheable
if ((inputLP->isCacheable()) && (predIdSet == NULL) )
{
CANodeIdSet combinedSet = jbbc;
// get the nodeIdSet of the outer child, if not already given. This
// along with the present jbbc is used as a key in the cache
CANodeIdSet * inputNodeSet;
inputNodeSet = inputLP->getNodeSet();
// if inLP are cacheable these should have a nodeSet attached
CCMPASSERT(inputNodeSet != NULL);
if (inputNodeSet)
{
combinedSet.insert(*inputNodeSet);
// if estLogProp for all local predicates is required,
// then it might already exist in the cache
outputEstLogProp = getCachedStatistics(&combinedSet);
}
}
if (outputEstLogProp == NULL)
{
// 2. properties do not exist in the cache, so synthesize them.
//if specified by the user apply those predicates,
// else apply predicates in the original expr
NodeAnalysis * jbbcNode = jbbc.getNodeAnalysis();
TableAnalysis * tableAnalysis = jbbcNode->getTableAnalysis();
if (tableAnalysis && predIdSet)
{
TableDesc * tableDesc = tableAnalysis->getTableDesc();
const QualifiedName& qualName =
tableDesc->getNATable()->getTableName();
CorrName name(qualName, STMTHEAP);
Scan *scanExpr = new STMTHEAP Scan(name, tableDesc, REL_SCAN, STMTHEAP);
Cardinality rc = tableDesc->getNATable()->getEstRowCount();
const CardinalityHint* cardHint = tableDesc->getCardinalityHint();
if ( cardHint )
rc = (cardHint->getScanCardinality()).getValue();
if ( !cardHint && tableDesc->getNATable()->isHbaseTable() ) {
NATable* nt = (NATable*)(tableDesc->getNATable());
StatsList* statsList = nt->getColStats();
if ( statsList && statsList->entries() > 0 ) {
ColStatsSharedPtr cStatsPtr =
statsList->getSingleColumnColStats(0);
if ( cStatsPtr )
rc = (cStatsPtr->getRowcount()).getValue();
}
}
scanExpr->setBaseCardinality(MIN_ONE (rc));
GroupAttributes * gaExpr = new STMTHEAP GroupAttributes();
scanExpr->setSelectionPredicates(*predIdSet);
ValueIdSet requiredOutputs = jbbc.getNodeAnalysis()->\
getOriginalExpr()->getGroupAttr()->getCharacteristicOutputs();
gaExpr->setCharacteristicOutputs(requiredOutputs);
scanExpr->setGroupAttr(gaExpr);
gaExpr->setLogExprForSynthesis(scanExpr);
EstLogPropSharedPtr nonCacheableInLP(new (HISTHEAP) EstLogProp (*inputLP));
nonCacheableInLP->setCacheableFlag(FALSE);
scanExpr->synthLogProp();
outputEstLogProp = scanExpr->getGroupAttr()->outputLogProp(nonCacheableInLP);
}
else
{
NodeAnalysis * nodeAnalysis = jbbc.getNodeAnalysis();
RelExpr * relExpr = nodeAnalysis->getModifiedExpr();
if (relExpr == NULL)
relExpr = nodeAnalysis->getOriginalExpr();
// synthesize and cache estLogProp for the given inLP.
outputEstLogProp = relExpr->getGroupAttr()->outputLogProp(inputLP);
}
}
return outputEstLogProp;
} // getStatsForCANodeId
