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arangodb
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The Condition findIndexes now tries to find an index for each AND block and fills a list of indexes, iff there is any element in the list we are able to use a CombinedIndexRangeNode, if not we still have to use the EnumerateCollectionNode

This commit is contained in:
Michael Hackstein 2015-09-25 11:45:31 +02:00
parent 6a11ad28ee
commit 6eb23f14f4
2 changed files with 15 additions and 16 deletions
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29
arangod/Aql/Condition.cpp
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@ -166,13 +166,18 @@ void Condition::andCombine (AstNode const* node) {
/// @brief locate indices for each condition
////////////////////////////////////////////////////////////////////////////////
void Condition::findIndexes (EnumerateCollectionNode const* node) {
void Condition::findIndexes (EnumerateCollectionNode const* node, std::vector<Index*> usedIndexes) {
// We can only start after DNF transform
TRI_ASSERT(_root->type == NODE_TYPE_OPERATOR_NARY_OR);
Variable const* reference = node->outVariable();
for (size_t i = 0; i < _root->numMembers(); ++i) {
setIndexForAndNode(_root->getMember(i), reference, node);
setIndexForAndNode(_root->getMember(i), reference, node, usedIndexes));
if (i != usedIndexes.size()) {
// We are not able to find an index for this AND block. Sorry we have to abort here
usedIndexes.clear();
break;
}
}
}
@ -181,27 +186,21 @@ void Condition::setIndexForAndNode (AstNode const* node, Variable const* referen
TRI_ASSERT(node->type == NODE_TYPE_OPERATOR_NARY_AND);
std::vector<Index*> indexes = colNode->collection()->getIndexes();
std::vector<Index*> matching;
std::vector<std::string> sortAttributes; // TODO has to be internal
double bestCost = -1.0; // All costs are > 0, so if we have found one we can use it.
Index* bestIndex;
for (auto& idx : indexes) {
double estimatedCost;
if (idx->canServeForConditionNode(node, reference, &sortAttributes, estimatedCost)) {
matching.emplace_back(idx);
if (bestCost < estimatedCost) {
bestIndex = idx;
}
}
}
std::cout << "We can use indexes for var: " << reference->name << " in collection " << colNode->collection()->getName() << ":" << std::endl;
for (auto& idx : matching) {
std::cout << idx->toJson() << std::endl;
/*
std::cout << "Type" << idx->type;
if (idx->hasSelectivityEstimate()) {
std::cout << " Estimate: " << idx->selectivityEstimate();
}
std::cout << std::endl;
*/
}
std::cout << std::endl;
std::cout << "We use: " << bestIndex->toJson() << std::endl;
}
////////////////////////////////////////////////////////////////////////////////

2
arangod/Aql/Condition.h
View File

@ -172,7 +172,7 @@ namespace triagens {
/// @brief locate indices which can be used for conditions
////////////////////////////////////////////////////////////////////////////////
void findIndexes (EnumerateCollectionNode const*);
void findIndexes (EnumerateCollectionNode const*, std::vector<Index*>);
////////////////////////////////////////////////////////////////////////////////
/// @brief dump the condition