Module org.apache.jena.serviceplugins

Package org.apache.jena.sparql.service.enhancer.impl

Class BatchQueryRewriter

java.lang.Object

org.apache.jena.sparql.service.enhancer.impl.BatchQueryRewriter

public class BatchQueryRewriter
extends Object

Rewriter for instantiating a query such that a list of initial bindings are injected. In general, there are several rewriting strategies for that purpose and their applicability depends on the operations used in of the query:

• Union/Substitution strategy: The is perhaps the most reliable (and also most verbose) strategy: It creates a union query where for every input binding a union member is obtained by substituting the original query with it
• Join strategy: The input bindings are collected into a VALUES block and placed on the left hand size of a join with an adjusted version of the original query - not yet supported
• Filter strategy: Input bindings are turned into a disjunctive filter expression - not yet supported

Constructor Summary

Constructors

Constructor	Description
BatchQueryRewriter(OpServiceInfo serviceInfo, org.apache.jena.sparql.core.Var idxVar, boolean sequentialUnion, boolean orderRetainingUnion, boolean omitEndMarker)

Method Summary

Modifier and Type	Method	Description
org.apache.jena.sparql.core.Var	getIdxVar()	The index var used by this rewriter
static boolean	isRemoteEndMarker(int id)
static boolean	isRemoteEndMarker(Integer id)
BatchQueryRewriteResult	rewrite(org.apache.jena.sparql.service.enhancer.impl.Batch<Integer,PartitionRequest<org.apache.jena.sparql.engine.binding.Binding>> batchRequest)
static Set<org.apache.jena.sparql.core.Var>	seenVars(Collection<PartitionRequest<org.apache.jena.sparql.engine.binding.Binding>> batchRequest)

Methods inherited from class java.lang.Object

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

Constructor Details

BatchQueryRewriter

public BatchQueryRewriter(OpServiceInfo serviceInfo,
 org.apache.jena.sparql.core.Var idxVar,
 boolean sequentialUnion,
 boolean orderRetainingUnion,
 boolean omitEndMarker)

Method Details

isRemoteEndMarker

public static boolean isRemoteEndMarker(int id)

isRemoteEndMarker

public static boolean isRemoteEndMarker(Integer id)

getIdxVar

public org.apache.jena.sparql.core.Var getIdxVar()

The index var used by this rewriter

seenVars

public static Set<org.apache.jena.sparql.core.Var> seenVars(Collection<PartitionRequest<org.apache.jena.sparql.engine.binding.Binding>> batchRequest)

rewrite

public BatchQueryRewriteResult rewrite(org.apache.jena.sparql.service.enhancer.impl.Batch<Integer,PartitionRequest<org.apache.jena.sparql.engine.binding.Binding>> batchRequest)