org.objectweb.medor.eval.api
Interface QueryEvaluator

All Known Implementing Classes:
MedorEvaluator

public interface QueryEvaluator

This interface represents the MEDOR evaluator. It permits to evaluate an evaluable (optimized) query Tree.


Method Summary
 TupleCollection evaluate(ParameterOperand[] parameters, ConnectionResources ressources)
          Launch the evaluation of a query.
 TupleCollection evaluate(ParameterOperand[] parameters, ConnectionResources ressources, PrefetchBuffer pb)
          Launch the evaluation of a query.
 long getCacheSize()
           
 QueryTree getQueryTree()
           
 ConnectionResources getRequiredConnectionResources()
           
 WrapperFactory getWrapperFactory()
          Returns the associated WrapperFactory.
 

Method Detail

evaluate

public TupleCollection evaluate(ParameterOperand[] parameters,
                                ConnectionResources ressources)
                         throws EvaluationException
Launch the evaluation of a query.

Parameters:
parameters - is the array of query parameter (Never null).
ressources - is a ConnectionResources containing associations between the DataStore names used in the QueryTree and the connection objects to use for the evaluation.It can be null.
Throws:
EvaluationException

evaluate

public TupleCollection evaluate(ParameterOperand[] parameters,
                                ConnectionResources ressources,
                                PrefetchBuffer pb)
                         throws EvaluationException
Launch the evaluation of a query. This method is able to prefetch data of the query in a prefetch buffer.

Parameters:
parameters - is the array of query parameter (Never null).
ressources - is a ConnectionResources containing associations between the DataStore names used in the QueryTree and the connection objects to use for the evaluation.It can be null.
pb - is the prefetch buffer which must be fill with query results. If this parameter is null then no data prefetching is done.
Throws:
EvaluationException

getRequiredConnectionResources

public ConnectionResources getRequiredConnectionResources()

getCacheSize

public long getCacheSize()
Returns:
the cache size used in different node of the QueryNode tree.

getQueryTree

public QueryTree getQueryTree()
Returns:
the evaluable (optimized) query tree.

getWrapperFactory

public WrapperFactory getWrapperFactory()
Returns the associated WrapperFactory. This is used to be able to bind specific Wrappers to DataStore types.

Returns:
the associated WrapperFactory