org.objectweb.medor.eval.api
Interface QueryEvaluator
- MedorEvaluator
public interface QueryEvaluator
This interface represents the MEDOR evaluator. It permits to evaluate an
evaluable (optimized) query Tree.
evaluate
public TupleCollection evaluate(ParameterOperand[] parameters,
ConnectionResources ressources,
Map evalMDMap)
throws EvaluationException
Launch the evaluation of a query.
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.evalMDMap
- contains a map associating an EvaluationMetaData object
to each of the query nodes of the query tree currently associated to the
QueryEvaluator.
evaluate
public TupleCollection evaluate(ParameterOperand[] parameters,
ConnectionResources ressources,
PrefetchBuffer pb,
Map evalMDMap)
throws EvaluationException
Launch the evaluation of a query. This method is able to prefetch data
of the query in a prefetch buffer.
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.
getCacheSize
public long getCacheSize()
- the cache size used in different node of the QueryNode tree.
getQueryTree
public QueryTree getQueryTree()
- the evaluable (optimized) query tree associated to the current
QueryEvaluator.
getWrapperFactory
public WrapperFactory getWrapperFactory()
Returns the associated WrapperFactory. This is used to be able to
bind specific Wrappers to DataStore types.
- the associated WrapperFactory