com.clarkparsia.pellet.sparqldl.engine

Class QueryEngine

java.lang.Object

com.clarkparsia.pellet.sparqldl.engine.QueryEngine

public class QueryEngine
extends Object

Title: Query Engine for SPARQL-DL

Description:

Copyright: Copyright (c) 2007

Company: Clark & Parsia, LLC.

Author:

Petr Kremen

Field Summary

Fields

Modifier and Type	Field and Description
static Logger	log
static CoreStrategy	STRATEGY

Constructor Summary

Constructors

Constructor and Description
QueryEngine()

Method Summary

Modifier and Type	Method and Description
static boolean	checkGround(QueryAtom atom, KnowledgeBase kb)
static QueryResult	exec(Query query)
static QueryResult	exec(Query query, KnowledgeBase kb)
static boolean	execBooleanABoxQuery(Query query) Executes all boolean ABox atoms
static QueryExec	getQueryExec()
static CoreStrategy	getStrategy(QueryAtom core)
static List<Query>	split(Query query) If a query has disconnected components such as C(x), D(y) then it should be answered as two separate queries.
static boolean	supports(Query query, KnowledgeBase kb)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

log

public static Logger log

STRATEGY

public static CoreStrategy STRATEGY

Constructor Detail

QueryEngine

public QueryEngine()

Method Detail

getQueryExec

public static QueryExec getQueryExec()

supports

public static boolean supports(Query query,
                               KnowledgeBase kb)

exec

public static QueryResult exec(Query query,
                               KnowledgeBase kb)

exec

public static QueryResult exec(Query query)

split

public static List<Query> split(Query query)

If a query has disconnected components such as C(x), D(y) then it should be answered as two separate queries. The answers to each query should be combined at the end by taking Cartesian product.(we combine results on a tuple basis as results are iterated. This way we avoid generating the full Cartesian product. Splitting the query ensures the correctness of the answer, e.g. rolling-up technique becomes applicable.

Parameters:

query - Query to be split

Returns:

List of queries (contains the initial query if the initial query is connected)

getStrategy

public static CoreStrategy getStrategy(QueryAtom core)

execBooleanABoxQuery

public static boolean execBooleanABoxQuery(Query query)

Executes all boolean ABox atoms

Parameters:

query -

Returns:

checkGround

public static boolean checkGround(QueryAtom atom,
                                  KnowledgeBase kb)