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

public class GraphRDB

extends 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 String	DEFAULT The name used for the default graph.
protected IRDBDriver	m_driver
protected DBPrefixMappingImpl	m_prefixMapping
protected DBPropGraph	m_properties
protected int	m_reificationBehaviour
protected Reifier	m_reifier
protected List	m_specializedGraphReifiers
protected List	m_specializedGraphs
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

capabilities, closed, gem, reifier, style

Constructor Summary

GraphRDB(IDBConnection con, String graphID, Graph requestedProperties, boolean isNew)
Deprecated. Please use the alternate constructor and choose the desired reification behaviour.

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

Method Summary

void	add(List triples) Add a list of triples.
void	addSubjectOrigin(RDFNode subject, Integer graphID)
protected void	checkOpen()
void	clearSubjectOrigin()
GraphRDB	cloneGraph()
void	close()
boolean	contains(Node s, Node p, Node o)
boolean	contains(Triple t)
void	delete(List triples) Delete a list of triples.
ExtendedIterator	find(TripleMatch m)
BulkUpdateHandler	getBulkUpdateHandler()
IDBConnection	getConnection() Return the connection
boolean	getDoDuplicateCheck() Get the value of DoDuplicateCheck
int	getGraphID()
String	getName()
Node	getNode() Returns the Node for this model in the system properties graph.
PrefixMapping	getPrefixMapping()
ExtendedIterator	getPropertyTriples() Returns triples that describe this graph in the system properties graph.
Reifier	getReifier()
Iterator	getSpecializedGraphs() Return an iterator over the specialized graphs for this graph
Integer	getSubjectOrigin(RDFNode subject)
TransactionHandler	getTransactionHandler()
protected boolean	isOpen()
void	performAdd(Triple t)
void	performDelete(Triple t)
QueryHandler	queryHandler()
int	reificationBehavior() Return the reification behavior (GraphRDB) for this graph
void	remove() Remove this Graph entirely from the database.
void	setDoDuplicateCheck(boolean bool) Set the value of DoDuplicateCheck.
void	setDriver(IRDBDriver driver)
int	size()
static int	styleRDB(Reifier.Style 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, containsByFind, delete, dependsOn, find, getCapabilities, getEventManager, isEmpty, isIsomorphicWith, notifyAdd, notifyDelete, toString, toString

Methods inherited from class java.lang.Object

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

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

delete, dependsOn, find, getCapabilities, getEventManager, isEmpty, isIsomorphicWith

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

add

Field Detail

DEFAULT

public static final String DEFAULT

The name used for the default graph.

See Also:

Constant Field Values

m_driver

protected IRDBDriver m_driver

m_properties

protected DBPropGraph m_properties

m_prefixMapping

protected DBPrefixMappingImpl m_prefixMapping

m_specializedGraphs

protected List m_specializedGraphs

m_specializedGraphReifiers

protected List m_specializedGraphReifiers

m_reifier

protected Reifier m_reifier

m_reificationBehaviour

protected int m_reificationBehaviour

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,
                String graphID,
                Graph requestedProperties,
                boolean isNew)

Deprecated. Please use the alternate constructor and choose the desired reification behaviour.

Construct a new GraphRDB using an unusual reification style.

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 ).

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

GraphRDB

public GraphRDB(IDBConnection con,
                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

addSubjectOrigin

public void addSubjectOrigin(RDFNode subject,
                             Integer graphID)

getSubjectOrigin

public Integer getSubjectOrigin(RDFNode subject)

clearSubjectOrigin

public void clearSubjectOrigin()

setDriver

public void setDriver(IRDBDriver driver)

getGraphID

public int getGraphID()

getName

public String getName()

cloneGraph

public GraphRDB cloneGraph()

styleRDB

public static int styleRDB(Reifier.Style style)

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

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 ExtendedIterator 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

isOpen

protected boolean isOpen()

checkOpen

protected void checkOpen()

performAdd

public void performAdd(Triple t)

add

public void add(List triples)

Add a list of triples.

Parameters:

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

performDelete

public void performDelete(Triple t)

delete

public void delete(List triples)

Delete a list of triples.

Parameters:

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

size

public int size()

Specified by:

size in interface Graph

contains

public boolean contains(Triple t)

Specified by:

contains in interface Graph

contains

public boolean contains(Node s,
                        Node p,
                        Node o)

Specified by:

contains in interface Graph

find

public ExtendedIterator find(TripleMatch m)

Specified by:

find in interface Graph

getBulkUpdateHandler

public BulkUpdateHandler getBulkUpdateHandler()

Specified by:

getBulkUpdateHandler in interface Graph

getReifier

public Reifier getReifier()

Specified by:

getReifier in interface Graph

getPrefixMapping

public PrefixMapping getPrefixMapping()

Specified by:

getPrefixMapping in interface Graph

getTransactionHandler

public TransactionHandler getTransactionHandler()

Specified by:

getTransactionHandler in interface Graph

close

public void close()

Specified by:

close in interface Graph

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).

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 Iterator getSpecializedGraphs()

Return an iterator over the specialized graphs for this graph

Returns:

Iterator over the list of specialized graphs.

queryHandler

public QueryHandler queryHandler()

Specified by:

queryHandler in interface Graph

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