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arangodb
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Cost estimates: IndexRangeNodes without range have to be more expensive than ones with.

This commit is contained in:
Willi Goesgens 2014-09-05 14:23:25 +02:00
parent 4b41b449f5
commit 02207d5f70
2 changed files with 12 additions and 4 deletions
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8
arangod/Aql/ExecutionNode.cpp
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@ -638,6 +638,7 @@ double IndexRangeNode::estimateCost () {
_dependencies.at(0)->getCost();
double cost = 1;
size_t count = 0;
if (_index->_type == TRI_IDX_TYPE_HASH_INDEX) {
return oldCost / 1000;
@ -648,17 +649,24 @@ double IndexRangeNode::estimateCost () {
if (x.is1ValueRangeInfo()) {
if (!_index->_unique) {
cost *= oldCost / 100;
count ++;
}
}
else {
cost *= oldCost / 10;
count ++;
}
}
else if (!(x._low._undefined && x._high._undefined)){
cost *= oldCost / 2;
count ++;
}
}
}
if (count == 0) {
// no ranges? so this is unlimited -> has to be more expensive
cost *= oldCost;
}
return cost;
}

8
arangod/Aql/OptimizerRules.cpp
View File

@ -70,13 +70,13 @@ int triagens::aql::removeRedundantSorts (Optimizer* opt,
auto other = static_cast<SortNode*>(current)->getSortInformation(plan);
switch (sortInfo.isCoveredBy(other)) {
case triagens::aql::SortInformation::unequal:
case SortInformation::unequal:
break;
case triagens::aql::SortInformation::otherSupersedes:
case SortInformation::otherSupersedes:
toUnlink.insert(current);
break;
case triagens::aql::SortInformation::weSupersede:
case triagens::aql::SortInformation::allEqual:
case SortInformation::weSupersede:
case SortInformation::allEqual:
// the sort at the start of the pipeline makes the sort at the end
// superfluous, so we'll remove it
toUnlink.insert(n);