com.hp.hpl.jena.db
Class GraphRDB

java.lang.Object
  com.hp.hpl.jena.graph.impl.GraphBase
      com.hp.hpl.jena.db.GraphRDB

All Implemented Interfaces:

Graph, GraphAdd, com.hp.hpl.jena.graph.impl.GraphWithPerform

public class GraphRDB
extends com.hp.hpl.jena.graph.impl.GraphBase
implements Graph

A persistent Graph implementation using a relational database for storage.

This graph stores data persistently in a relational database. It supports the full Graph interface and should operate just like a GraphMem.

Internally, each GraphRDB keeps a list of specialized graphs. For each operation, it works through the list of graphs attempting to perform the operation on each one.

The intention is that each type of specialized graph is optimized for a different type of triple. For example, one type of specialied graph might be optimized for storing triples in a particular ontology. The last specialized graph in the list is always a generic one that can handle any valid RDF triple.

The order of the specialized graphs is consistent and immutable after the graph is constructed. This aids optimization. For example, if a specialized graph is asked to perform an operatin on a triple, and it knows that it would have added it if asked, then it can advise the calling GraphRDB that the operaton is complete even though it doesn't know anything about other specialized graphs later in the list.

Since:

Jena 2.0

Version:

$Revision: 1.1 $

Author:

csayers (based in part on GraphMem by bwm).

Field Summary

static java.lang.String	DEFAULT The name used for the default graph.
static int	OPTIMIZE_ALL_REIFICATIONS_AND_HIDE_NOTHING Optimize all triples representing part or all of a reified statement; this is the recommended option.
static int	OPTIMIZE_AND_HIDE_FULL_AND_PARTIAL_REIFICATIONS Optimize and hide any triples representing part or all of a reified statement.
static int	OPTIMIZE_AND_HIDE_ONLY_FULL_REIFICATIONS Optimize and hide only fully reified statements added via the Reifier interface, use only for backward-compatability with Jena1.

Fields inherited from class com.hp.hpl.jena.graph.impl.GraphBase

TOSTRING_TRIPLE_BASE, TOSTRING_TRIPLE_LIMIT

Fields inherited from interface com.hp.hpl.jena.graph.Graph

emptyGraph

Constructor Summary

GraphRDB(IDBConnection con, java.lang.String graphID, Graph requestedProperties, int reificationBehaviour, boolean isNew)
Construct a new GraphRDB

Method Summary

void	add(java.util.List<Triple> triples) Add a list of triples.
void	clear() Remove all statements from this graph.
void	close() Free all resources, any further use of this Graph is an error.
com.hp.hpl.jena.db.impl.DBQueryHandler	DBqueryHandler()
void	delete(java.util.List<Triple> triples) Delete a list of triples.
BulkUpdateHandler	getBulkUpdateHandler() returns this Graph's bulk-update handler
Capabilities	getCapabilities() Database graphs do not presently support the equivalence of plain string literals and xsd:string literals (and other typed literals in general).
IDBConnection	getConnection() Return the connection
boolean	getDoDuplicateCheck() Get the value of DoDuplicateCheck
boolean	getDoFastpath() Get the value of DoFastpath.
Node	getNode() Returns the Node for this model in the system properties graph.
PrefixMapping	getPrefixMapping() returns this Graph's prefix mapping.
com.hp.hpl.jena.util.iterator.ExtendedIterator<Triple>	getPropertyTriples() Returns triples that describe this graph in the system properties graph.
boolean	getQueryFullReified() Get the value of QueryFullReified.
boolean	getQueryOnlyAsserted() Get the value of QueryOnlyAsserted.
boolean	getQueryOnlyReified() Get the value of QueryOnlyReified.
Reifier	getReifier() returns this Graph's reifier.
java.util.Iterator<com.hp.hpl.jena.db.impl.SpecializedGraph>	getSpecializedGraphs() Return an iterator over the specialized graphs for this graph
TransactionHandler	getTransactionHandler() returns this Graph's transaction handler
boolean	graphBaseContains(Triple t)
com.hp.hpl.jena.util.iterator.ExtendedIterator<Triple>	graphBaseFind(TripleMatch m)
int	graphBaseSize()
boolean	isClosed() Answer true iff .close() has been called onn this Graph.
void	performAdd(Triple t)
void	performDelete(Triple t)
QueryHandler	queryHandler() returns this Graph's query handler
int	reificationBehavior() Return the reification behavior (GraphRDB) for this graph
int	reifierSize()
com.hp.hpl.jena.util.iterator.ExtendedIterator<Triple>	reifierTriples(TripleMatch m)
void	remove() Remove this Graph entirely from the database.
void	setDoDuplicateCheck(boolean bool) Set the value of DoDuplicateCheck.
void	setDoFastpath(boolean val) Set the value of DoFastpath.
void	setDoImplicitJoin(boolean val) Set the value of DoImplicitJoin.
void	setQueryFullReified(boolean opt) Set the value of QueryFullReified.
void	setQueryOnlyAsserted(boolean opt) Set the value of QueryOnlyAsserted.
void	setQueryOnlyReified(boolean opt) Set the value of QueryOnlyReified.
static ReificationStyle	styleRDB(int behaviour) Answer the reification style corresponding to the DB behaviour integer.
static int	styleRDB(ReificationStyle style) Answer the integer representing the RDB reifier style given the Reifier style.

Methods inherited from class com.hp.hpl.jena.graph.impl.GraphBase

add, contains, contains, delete, dependsOn, find, find, forTestingOnly_graphBaseFind, getEventManager, getStatisticsHandler, isEmpty, isIsomorphicWith, notifyAdd, notifyDelete, size, toString, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.hp.hpl.jena.graph.Graph

contains, contains, delete, dependsOn, find, find, getEventManager, getStatisticsHandler, isEmpty, isIsomorphicWith, size

Methods inherited from interface com.hp.hpl.jena.graph.GraphAdd

add

Field Detail

DEFAULT

public static final java.lang.String DEFAULT

The name used for the default graph.

See Also:

Constant Field Values

OPTIMIZE_ALL_REIFICATIONS_AND_HIDE_NOTHING

public static final int OPTIMIZE_ALL_REIFICATIONS_AND_HIDE_NOTHING

Optimize all triples representing part or all of a reified statement; this is the recommended option.

This is the best choice in almost every case. It optimizes all reified triples regardless of how they are added to the graph, provides a simple interface, and is quite efficient.

With this choice, if you do add(A) then contains(A) will return true for all A.

See Also:

Constant Field Values

OPTIMIZE_AND_HIDE_FULL_AND_PARTIAL_REIFICATIONS

public static final int OPTIMIZE_AND_HIDE_FULL_AND_PARTIAL_REIFICATIONS

Optimize and hide any triples representing part or all of a reified statement.

This optimizes all triples but hides them so they are visible only via the reifier interface. There is no significant performance advantage in using this option and it is not recommended. It is included only for compatability with in-memory graphs.

Note that it will also cause unexpected behaviour, for example, if you do: add(new Triple( s, RDF.predicate, o)) then that triple will be hidden and a subsequent call to contains, find, or size will not show it's presence. The only way to see that statement is to use Reifier.getHiddenTriples.

See Also:

Constant Field Values

OPTIMIZE_AND_HIDE_ONLY_FULL_REIFICATIONS

public static final int OPTIMIZE_AND_HIDE_ONLY_FULL_REIFICATIONS

Optimize and hide only fully reified statements added via the Reifier interface, use only for backward-compatability with Jena1.

This treats triples added through the Reifier interface as distinct from those added using the normal Graph.add function. Those added via the reifier interface will be optimized and hidden from view. Those added via Graph.add will not be optimized and will be visible.

Since many of the techniques for adding triple to Graphs use Graph.add, and that is never optimized, this is not usually a good choice. It is included only for backward compability with Jena 1. There is no performance advantage in using this option.

See Also:

Constant Field Values

Constructor Detail

GraphRDB

public GraphRDB(IDBConnection con,
                java.lang.String graphID,
                Graph requestedProperties,
                int reificationBehaviour,
                boolean isNew)

Construct a new GraphRDB

Parameters:

con - an open connection to the database

graphID - is the name of a graph or GraphRDB.DEFAULT

requestedProperties - a set of default properties. (May be null, if non-null should be a superset of the properties obtained by calling ModelRDB.getDefaultModelProperties ).

reificationBehaviour - specifies how this graph should handle reified triples. The options are OPTIMIZE_ALL_REIFICATIONS_AND_HIDE_NOTHING (strongly recommended), OPTIMIZE_AND_HIDE_FULL_AND_PARTIAL_REIFICATIONS (included only for full compatability with all the options for in-memory Graphs), OPTIMIZE_AND_HIDE_ONLY_FULL_REIFICATIONS (included only for compatability with older jena1-style usage).

isNew - is true if the graph doesn't already exist and false otherwise. (If unsure, test for existance by using IDBConnection.containsGraph ).

Method Detail

styleRDB

public static int styleRDB(ReificationStyle style)

Answer the integer representing the RDB reifier style given the Reifier style.

styleRDB

public static ReificationStyle styleRDB(int behaviour)

Answer the reification style corresponding to the DB behaviour integer.

getCapabilities

public Capabilities getCapabilities()

Database graphs do not presently support the equivalence of plain string literals and xsd:string literals (and other typed literals in general).

Specified by:

getCapabilities in interface Graph

Overrides:

getCapabilities in class com.hp.hpl.jena.graph.impl.GraphBase

See Also:

Graph.getCapabilities()

getNode

public Node getNode()

Returns the Node for this model in the system properties graph. The properties of each GraphRDB (things like how it is stored in the database) are themelves stored in a system Graph. This function returns the Node which represents this GraphRDB in the system Graph.

Since:

Jena 2.0

getPropertyTriples

public com.hp.hpl.jena.util.iterator.ExtendedIterator<Triple> getPropertyTriples()

Returns triples that describe this graph in the system properties graph. The properties of each GraphRDB (things like how it is stored in the database) are stored as triples in a system Graph. This function returns those triples.

Since:

Jena 2.0

isClosed

public boolean isClosed()

Description copied from interface: Graph

Answer true iff .close() has been called onn this Graph.

Specified by:

isClosed in interface Graph

Overrides:

isClosed in class com.hp.hpl.jena.graph.impl.GraphBase

performAdd

public void performAdd(Triple t)

Specified by:

performAdd in interface com.hp.hpl.jena.graph.impl.GraphWithPerform

Overrides:

performAdd in class com.hp.hpl.jena.graph.impl.GraphBase

add

public void add(java.util.List<Triple> triples)

Add a list of triples.

Parameters:

triples - List to be added. This is unchanged by the call

performDelete

public void performDelete(Triple t)

Specified by:

performDelete in interface com.hp.hpl.jena.graph.impl.GraphWithPerform

Overrides:

performDelete in class com.hp.hpl.jena.graph.impl.GraphBase

delete

public void delete(java.util.List<Triple> triples)

Delete a list of triples.

Parameters:

triples - List to be deleted. This is unchanged by the call.

graphBaseSize

public int graphBaseSize()

Overrides:

graphBaseSize in class com.hp.hpl.jena.graph.impl.GraphBase

graphBaseContains

public boolean graphBaseContains(Triple t)

Overrides:

graphBaseContains in class com.hp.hpl.jena.graph.impl.GraphBase

graphBaseFind

public com.hp.hpl.jena.util.iterator.ExtendedIterator<Triple> graphBaseFind(TripleMatch m)

Specified by:

graphBaseFind in class com.hp.hpl.jena.graph.impl.GraphBase

reifierTriples

public com.hp.hpl.jena.util.iterator.ExtendedIterator<Triple> reifierTriples(TripleMatch m)

Overrides:

reifierTriples in class com.hp.hpl.jena.graph.impl.GraphBase

reifierSize

public int reifierSize()

Overrides:

reifierSize in class com.hp.hpl.jena.graph.impl.GraphBase

getBulkUpdateHandler

public BulkUpdateHandler getBulkUpdateHandler()

Description copied from interface: Graph

returns this Graph's bulk-update handler

Specified by:

getBulkUpdateHandler in interface Graph

Overrides:

getBulkUpdateHandler in class com.hp.hpl.jena.graph.impl.GraphBase

getReifier

public Reifier getReifier()

Description copied from interface: Graph

returns this Graph's reifier. Each call on a given Graph gets the same Reifier object.

Specified by:

getReifier in interface Graph

Overrides:

getReifier in class com.hp.hpl.jena.graph.impl.GraphBase

getPrefixMapping

public PrefixMapping getPrefixMapping()

Description copied from interface: Graph

returns this Graph's prefix mapping. Each call on a given Graph gets the same PrefixMapping object, which is the one used by the Graph.

Specified by:

getPrefixMapping in interface Graph

Overrides:

getPrefixMapping in class com.hp.hpl.jena.graph.impl.GraphBase

getTransactionHandler

public TransactionHandler getTransactionHandler()

Description copied from interface: Graph

returns this Graph's transaction handler

Specified by:

getTransactionHandler in interface Graph

Overrides:

getTransactionHandler in class com.hp.hpl.jena.graph.impl.GraphBase

close

public void close()

Description copied from interface: Graph

Free all resources, any further use of this Graph is an error.

Specified by:

close in interface Graph

Overrides:

close in class com.hp.hpl.jena.graph.impl.GraphBase

remove

public void remove()

Remove this Graph entirely from the database. This operation is unique to GraphRDB - it removes all mention of this graph from the database - after removing a graph it is recommended to immediately call close() (there is no other useful operation that may be performed, and so no reason to keep the Graph around).

clear

public void clear()

Remove all statements from this graph.

getConnection

public IDBConnection getConnection()

Return the connection

Returns:

IDBConnection for the database on which this graph is stored. Returns null if the connection has not yet been estabilished.

reificationBehavior

public int reificationBehavior()

Return the reification behavior (GraphRDB) for this graph

Returns:

integer that defines the reification behavior for this graphRDB.

getSpecializedGraphs

public java.util.Iterator<com.hp.hpl.jena.db.impl.SpecializedGraph> getSpecializedGraphs()

Return an iterator over the specialized graphs for this graph

Returns:

Iterator over the list of specialized graphs.

queryHandler

public QueryHandler queryHandler()

Description copied from interface: Graph

returns this Graph's query handler

Specified by:

queryHandler in interface Graph

Overrides:

queryHandler in class com.hp.hpl.jena.graph.impl.GraphBase

DBqueryHandler

public com.hp.hpl.jena.db.impl.DBQueryHandler DBqueryHandler()

getDoDuplicateCheck

public boolean getDoDuplicateCheck()

Get the value of DoDuplicateCheck

Returns:

bool boolean

setDoDuplicateCheck

public void setDoDuplicateCheck(boolean bool)

Set the value of DoDuplicateCheck.

Parameters:

bool - boolean

setDoFastpath

public void setDoFastpath(boolean val)

Set the value of DoFastpath.

Parameters:

val - boolean

getDoFastpath

public boolean getDoFastpath()

Get the value of DoFastpath.

Returns:

boolean

setQueryOnlyAsserted

public void setQueryOnlyAsserted(boolean opt)

Set the value of QueryOnlyAsserted.

Parameters:

opt - boolean

getQueryOnlyAsserted

public boolean getQueryOnlyAsserted()

Get the value of QueryOnlyAsserted.

Returns:

boolean

setQueryOnlyReified

public void setQueryOnlyReified(boolean opt)

Set the value of QueryOnlyReified.

Parameters:

opt - boolean

getQueryOnlyReified

public boolean getQueryOnlyReified()

Get the value of QueryOnlyReified.

Returns:

boolean

setQueryFullReified

public void setQueryFullReified(boolean opt)

Set the value of QueryFullReified.

Parameters:

opt - boolean

getQueryFullReified

public boolean getQueryFullReified()

Get the value of QueryFullReified.

Returns:

boolean

setDoImplicitJoin

public void setDoImplicitJoin(boolean val)

Set the value of DoImplicitJoin.

Parameters:

val - boolean