org.openanzo.glitter.query
Interface QueryExecutor

All Known Implementing Classes:

ParallelQueryExecutor, SerialQueryExecutor

public interface QueryExecutor

A QueryExecutor implements the actual logic for orchestrating a QueryController, a SolutionGenerator, an RDFDataset, a QueryExecutionPlan, and other components to produce a result set.

Author:

lee

Method Summary

boolean	composedSolutions() Clients of an executor need to know whether the executor had a handle in putting together results, to know if reordering might be necessary.
SolutionSet	executeQuery() Executes the query, returning a result set.
void	initialize(EngineConfig config, QueryController controller, SolutionGenerator sg, QueryExecutionPlan plan) Initialize the executor with information on the query.

Method Detail

initialize

void initialize(EngineConfig config,
                QueryController controller,
                SolutionGenerator sg,
                QueryExecutionPlan plan)

Initialize the executor with information on the query.

Parameters:

config - The engine configuration in effect.

controller - The query controller with information on the parsed and prepared query.

sg - The backend solution generator.

plan - The query execution plan.

executeQuery

SolutionSet executeQuery()
                         throws GlitterException

Executes the query, returning a result set.

Returns:

A SolutionSet with the bindings from executing the query against an RDFDataset.

Throws:

GlitterException

composedSolutions

boolean composedSolutions()

Clients of an executor need to know whether the executor had a handle in putting together results, to know if reordering might be necessary. Executors are considered trustworthy, while backends may not be.

Returns:

true if results were composed from pieces provided by a backend; false if all results were generated by the backend.