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more accurate cost estimation for EnumerateListNode 

fixed typos
This commit is contained in:
Jan Steemann 2015-01-22 19:24:20 +01:00
parent fd3e123253
commit a5ff6aa05e
2 changed files with 38 additions and 6 deletions
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38
arangod/Aql/ExecutionNode.cpp
View File

@ -1269,12 +1269,46 @@ ExecutionNode* EnumerateListNode::clone (ExecutionPlan* plan,
double EnumerateListNode::estimateCost (size_t& nrItems) const {
size_t incoming = 0;
double depCost = _dependencies.at(0)->getCost(incoming);
nrItems = 100*incoming;
return depCost + 100.0 * incoming;
// Well, what can we say? The length of the list can in general
// only be determined at runtime... If we were to know that this
// list is constant, then we could maybe multiply by the length
// here... For the time being, we assume 100
size_t length = 100;
auto setter = _plan->getVarSetBy(_inVariable->id);
if (setter != nullptr &&
setter->getType() == ExecutionNode::CALCULATION) {
// list variable introduced by a calculation
auto expression = static_cast<CalculationNode*>(setter)->expression();
if (expression != nullptr) {
auto node = expression->node();
if (node->type == NODE_TYPE_ARRAY) {
// this one is easy
length = node->numMembers();
}
if (node->type == NODE_TYPE_RANGE) {
auto low = node->getMember(0);
auto high = node->getMember(1);
if (low->isConstant() &&
high->isConstant() &&
(low->isValueType(VALUE_TYPE_INT) || low->isValueType(VALUE_TYPE_DOUBLE)) &&
(high->isValueType(VALUE_TYPE_INT) || high->isValueType(VALUE_TYPE_DOUBLE))) {
// create a temporary range to determine the size
Range range(low->getIntValue(), high->getIntValue());
length = range.size();
}
}
}
}
nrItems = length * incoming;
return depCost + static_cast<double>(length) * incoming;
}
// -----------------------------------------------------------------------------

6
arangod/Aql/V8Expression.cpp
View File

@ -78,7 +78,7 @@ AqlValue V8Expression::execute (v8::Isolate* isolate,
std::vector<Variable*> const& vars,
std::vector<RegisterId> const& regs) {
size_t const n = vars.size();
TRI_ASSERT_EXPESNIVE(regs.size() == n); // assert same vector length
TRI_ASSERT_EXPENSIVE(regs.size() == n); // assert same vector length
bool const attributesPresent = ! attributes.empty();
@ -88,9 +88,7 @@ AqlValue V8Expression::execute (v8::Isolate* isolate,
auto const varname = vars[i]->name;
auto reg = regs[i];
TRI_ASSERT(! argv[reg].isEmpty());
auto type = argv[startPos + reg]._type;
TRI_ASSERT_EXPENSIVE(! argv[reg].isEmpty());
if (attributesPresent && argv[startPos + reg]._type == AqlValue::JSON) {
// check if we can get away with constructing a partial JSON object