Dataflow LogicalIndexScan::getDataflow()
{
if(!scan_projection_->AllPartitionBound()){
printf("Binded!\n");
Catalog::getInstance()->getBindingModele()->BindingEntireProjection(scan_projection_->getPartitioner(),DESIRIABLE_STORAGE_LEVEL);
}
dataflow_.attribute_list_ = scan_projection_->getAttributeList();
Partitioner* par = scan_projection_->getPartitioner();
dataflow_.property_.partitioner = DataflowPartitioningDescriptor(*par);
dataflow_.property_.commnication_cost = 0;
return dataflow_;
}
//LogicalProjection LogicalScan::getLogcialProjection()const{
// return logical_projection_;
//}
//can only scan all attributes in a projection
Dataflow LogicalScan::getDataflow(){
if(dataflow_==0)
dataflow_=new Dataflow();
else
return *dataflow_;
TableID table_id=scan_attribute_list_[0].table_id_;
TableDescriptor* table=Catalog::getInstance()->getTable(table_id);
if(target_projection_==0){
ProjectionOffset target_projection_off=-1;
unsigned int min_projection_cost = -1;
/*
* TODO: get real need column as scan_attribute_list_, otherwise, optimization don't work -Yu
*/
for(ProjectionOffset projection_off=0;projection_off<table->getNumberOfProjection();projection_off++){
ProjectionDescriptor* projection=table->getProjectoin(projection_off);
bool fail=false;
for(std::vector<Attribute>::iterator it=scan_attribute_list_.begin();it!=scan_attribute_list_.end();it++){
if(!projection->hasAttribute(*it)){
/*the attribute *it is not in the projection*/
fail=true;
break;
}
}
if(fail==true){
continue;
}
unsigned int projection_cost = projection->getProjectionCost();
//get the projection with minimum cost
if (min_projection_cost > projection_cost) {
target_projection_off = projection_off;
min_projection_cost = projection_cost;
cout<<"in "<<table->getNumberOfProjection()<<" projections, "
"projection "<<projection_off<<" has less cost:"<<projection_cost<<endl;
}
// projection_candidate.push_back(projection_off);
// break;
}
if(target_projection_off==-1){
/*fail to find a projection that contains all the scan attribute*/
printf("The current implementation does not support the scanning that involves more than one projection.\n");
assert(false);
}
target_projection_=table->getProjectoin(target_projection_off);
cout<<"in "<<table->getNumberOfProjection()<<" projections, "
"projection "<<target_projection_off<<" has min cost:"<<min_projection_cost<<endl;
}
if(!target_projection_->AllPartitionBound()){
Catalog::getInstance()->getBindingModele()->BindingEntireProjection(target_projection_->getPartitioner(),DESIRIABLE_STORAGE_LEVEL);
}
/*build the data flow*/
dataflow_->attribute_list_=scan_attribute_list_; /*attribute_list*/
Partitioner* par=target_projection_->getPartitioner();
dataflow_->property_.partitioner=DataflowPartitioningDescriptor(*par);
dataflow_->property_.commnication_cost=0;
return *dataflow_;
}
