com.hp.hpl.jena.db
Class GraphRDB

java.lang.Object
  extended bycom.hp.hpl.jena.graph.impl.GraphBase
      extended bycom.hp.hpl.jena.db.GraphRDB
All Implemented Interfaces:
Graph, GraphAdd

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: 1.32 $
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 interface com.hp.hpl.jena.graph.Graph
emptyGraph
 
Constructor Summary
GraphRDB(IDBConnection con, java.lang.String graphID, Graph requestedProperties, boolean isNew)
          Deprecated. Please use the alternate constructor and choose the desired reification behaviour.
GraphRDB(IDBConnection con, java.lang.String graphID, Graph requestedProperties, int reificationBehaviour, boolean isNew)
          Construct a new GraphRDB
 
Method Summary
 void add(java.util.List triples)
          Add a list of triples.
 void close()
          Free all resources, any further use of this Graph is an error.
 boolean contains(Node s, Node p, Node o)
          Answer true iff the graph contains a triple matching (s, p, o).
 boolean contains(Triple t)
          Answer true iff the graph contains a triple that t matches; t may be fluid.
 void delete(java.util.List triples)
          Delete a list of triples.
 ExtendedIterator find(TripleMatch m)
          Returns an iterator over all the Triples that match the triple pattern.
 BulkUpdateHandler getBulkUpdateHandler()
          returns this Graph's bulk-update handler
 IDBConnection getConnection()
          Return the connection
 boolean getDoDuplicateCheck()
          Get the value of DoDuplicateCheck
 Node getNode()
          Returns the Node for this model in the system properties graph.
 PrefixMapping getPrefixMapping()
          returns this Graph's prefix mapping.
 ExtendedIterator getPropertyTriples()
          Returns triples that describe this graph in the system properties graph.
 Reifier getReifier()
          returns this Graph's reifier.
 java.util.Iterator getSpecializedGraphs()
          Return an iterator over the specialized graphs for this graph
 TransactionHandler getTransactionHandler()
          returns this Graph's transaction handler
 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
 void remove()
          Remove this Graph entirely from the database.
 void setDoDuplicateCheck(boolean bool)
          Set the value of DoDuplicateCheck.
 int size()
          For a concrete graph this returns the number of triples in the graph.
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, delete, dependsOn, find, getCapabilities, getEventManager, isEmpty, isIsomorphicWith, notifyAdd, notifyDelete, 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
delete, dependsOn, find, getCapabilities, getEventManager, isEmpty, isIsomorphicWith
 
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,
                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,
                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.


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

performAdd

public void performAdd(Triple t)

add

public void add(java.util.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(java.util.List triples)
Delete a list of triples.

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

size

public int size()
Description copied from interface: Graph
For a concrete graph this returns the number of triples in the graph. For graphs which might infer additional triples it results an estimated lower bound of the number of triples. For example, an inference graph might return the number of triples in the raw data graph.

Specified by:
size in interface Graph
See Also:
Graph.size()

contains

public boolean contains(Triple t)
Description copied from interface: Graph
Answer true iff the graph contains a triple that t matches; t may be fluid.

Specified by:
contains in interface Graph

contains

public boolean contains(Node s,
                        Node p,
                        Node o)
Description copied from interface: Graph
Answer true iff the graph contains a triple matching (s, p, o). s/p/o may be concrete or fluid. Equivalent to find(s,p,o).hasNext, but an implementation is expected to optimise this in easy cases.

Specified by:
contains in interface Graph

find

public ExtendedIterator find(TripleMatch m)
Description copied from interface: Graph
Returns an iterator over all the Triples that match the triple pattern.

Specified by:
find in interface Graph
See Also:
Graph.find(TripleMatch)

getBulkUpdateHandler

public BulkUpdateHandler getBulkUpdateHandler()
Description copied from interface: Graph
returns this Graph's bulk-update handler

Specified by:
getBulkUpdateHandler in interface Graph

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

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

getTransactionHandler

public TransactionHandler getTransactionHandler()
Description copied from interface: Graph
returns this Graph's transaction handler

Specified by:
getTransactionHandler in interface Graph

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
See Also:
Graph.close()

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 java.util.Iterator 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
See Also:
Graph.queryHandler()

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


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