public QueryPlan GetQueryPlan(IDmObject parsedQuery, IQuery query, IQueryStore queryStore, MetadataIndex rowsEnumerator)
{
//Todo: Plan's cache's key decision (query-string based plan cache/optimizable-section based cache).
OrderedList <double, IProxyPredicate> sortedPlans = new OrderedList <double, IProxyPredicate>();
var optimizableQuery = parsedQuery as IFilterObject;
var criteria = AddQueryCriteria(parsedQuery, query.Parameters, queryStore);
var queryPlan = new QueryPlan {
Criteria = criteria
};
if (optimizableQuery != null && optimizableQuery.WherePredicate != null)
{
ITreePredicate whereExpression = optimizableQuery.WherePredicate;
ITreePredicate contractedExpression = whereExpression.Contract();
if (contractedExpression == null)
{
contractedExpression = whereExpression;
}
List <ITreePredicate> distribCombinations = new List <ITreePredicate>();
distribCombinations.Add(contractedExpression);
//Todo: Restrict this call if there doesn't exist a compound index.
while (contractedExpression.Expand() != null)
{
distribCombinations.Add(contractedExpression.Expand());
contractedExpression = contractedExpression.Expand();
}
foreach (var treePredicate in distribCombinations)
{
if (treePredicate is OrTreePredicate || treePredicate is AndTreePredicate)
{
break;
}
if (treePredicate is ComparisonPredicate)
{
DocumentKey documentKey = null;
if (((ComparisonPredicate)treePredicate).TryGetProxyKeyPredicate(rowsEnumerator, out documentKey))
{
IProxyPredicate optimizablePredicate = new ProxyPredicate(new KeyPredicate(documentKey, rowsEnumerator), treePredicate);
sortedPlans.Add(optimizablePredicate.Statistics[Statistic.ExpectedIO], optimizablePredicate);
queryPlan.Predicate = sortedPlans.FirstValues[0].GetExecutionPredicate(queryStore);
return(queryPlan);
}
}
}
foreach (var expressionState in distribCombinations)
{
IProxyPredicate optimizablePredicate = expressionState.GetProxyExecutionPredicate(_indexManager, queryStore, rowsEnumerator);
sortedPlans.Add(optimizablePredicate.Statistics[Statistic.ExpectedIO], optimizablePredicate);
//Todo: Add optimizedPredicate to the SortedList by the cost.
}
queryPlan.Predicate = sortedPlans.FirstValues[0].GetExecutionPredicate(queryStore);
}
else
{
if (criteria.GroupFields != null && criteria.GroupFields.Count == 1 && criteria.GroupFields[0] is AllField && criteria.ContainsAggregations)
{
if (criteria.Aggregations.Count == 1 && criteria.Aggregations[0].Aggregation is COUNT &&
criteria.Aggregations[0].Evaluation is AllEvaluable)
{
queryPlan.Criteria.GroupByField = null;
queryPlan.Predicate = new SpecialCountPredicate(rowsEnumerator.KeyCount);
queryPlan.IsSpecialExecution = true;
return(queryPlan);
}
}
//Todo:1 Projection variable-based index assigning (Functions' arguments + attributes).
queryPlan.Predicate = GetSelectAllPredicate(criteria, rowsEnumerator);
}
return(queryPlan);
}
public ICollection <QueryPlan> GetAllPlans(IDmObject parsedQuery, IQuery query, IQueryStore queryStore)
{
throw new System.NotImplementedException();
}
public ICollection <QueryPlan> GetAllPlans(IDmObject parsedQuery, IQuery query, IQueryStore queryStore)
{
//NO!
return(null);
}
public QueryPlan GetQueryPlan(IDmObject parsedQuery, IQuery query, IQueryStore queryStore, MetadataIndex rowEnumerator)
{
throw new System.NotImplementedException();
}
