public List <Row> show()
{
bind(null);
// TBD: route to optimizer here
QueryOption queryOpt = new QueryOption();
physicPlan_ = logicPlan_.DirectToPhysical(queryOpt);
logicPlan_.ResolveColumnOrdinal(outputs_);
// actual execution
var finalplan = new PhysicCollect(physicPlan_);
physicPlan_ = finalplan;
var context = new ExecContext(queryOpt);
Console.WriteLine(physicPlan_.Explain());
finalplan.ValidateThis();
var code = finalplan.Open(context);
code += finalplan.Exec(null);
code += finalplan.Close();
return(finalplan.rows_);
}