about this, should I create an issue? On Thu, Jul 21, 2011 at 5:15 AM, cyuczi eekc <cyuczie...@gmail.com> wrote:
> Ok there, I found out something new, if I do the count outside of the > transaction (ie. after tx.finish() ) then it works right, > ie. in a different example: > Node `one` has 100,100 out rels, time=7,954,653,001 > tx.finish() time=1,525,669,261 > Node `one` has 1,200,546 out rels > > And as long as I create relationships inside the transaction, it will > always show me(when I count) the number of added relationships + 100, even > if on previous program run I had a transaction with more added relationships > (ie. 200,000 as opposed to 100,000 now => shows 100,100) > ok, here's the latest sample program: > with this output ie. > Node `one` has 99,100 out rels, time=9,265,459,688 > tx.finish() time=1,221,787,378 > counting outside of transaction... > Node `one` has 1,399,546 out rels, time=353,716,303 > > > /** > * Licensed to Neo Technology under one or more contributor > * license agreements. See the NOTICE file distributed with > * this work for additional information regarding copyright > * ownership. Neo Technology licenses this file to you under > * the Apache License, Version 2.0 (the "License"); you may > * not use this file except in compliance with the License. > * You may obtain a copy of the License at > * > * http://www.apache.org/licenses/LICENSE-2.0 > * > * Unless required by applicable law or agreed to in writing, > * software distributed under the License is distributed on an > * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY > * KIND, either express or implied. See the License for the > * specific language governing permissions and limitations > * under the License. > */ > package org.neo4j.examples; > > import java.io.*; > import java.text.*; > > import org.neo4j.graphdb.*; > import org.neo4j.graphdb.index.*; > import org.neo4j.kernel.*; > > > > public class CalculateShortestPath { > > private static final int > SHOWINFO_IF_COUNTING_REL_TOOK_MORE_THAN_ns = 2 * 300; > private static final int > SHOWINFO_IF_REL_TOOK_MORE_THAN_ns = 30000; > private static final int SHOWEVERY_xTH_REL > = 10000; > private static final int HOWMANY_RELATIONSHIPS > = 99000; > > private static final String DB_PATH > = "neo4j-shortest-path"; > private static final String NAME_KEY > = "name"; > private static RelationshipType KNOWS > = DynamicRelationshipType > > .withName( "KNOWS" ); > > private static GraphDatabaseService graphDb; > private static Index<Node> indexService; > private static DecimalFormat commaDelimitedFormatter > = new DecimalFormat( "###,###" ); > > > public static String number( double val ) { > return commaDelimitedFormatter.format( val ); > } > > > public static void main( final String[] args ) { > // deleteFileOrDirectory( new File( DB_PATH ) );// XXX: > graphDb = new EmbeddedGraphDatabase( DB_PATH ); > indexService = graphDb.index().forNodes( "nodes" ); > registerShutdownHook(); > Transaction tx = graphDb.beginTx(); > Node one = getOrCreateNode( "one" ); > DynamicRelationshipType moo = DynamicRelationshipType.withName( > "moo" ); > try { > > for ( int i = 1; i <= HOWMANY_RELATIONSHIPS; i++ ) { > long start = System.nanoTime(); > Relationship rel = one.createRelationshipTo( > graphDb.createNode(), moo ); > // rel.setProperty( "relname", i ); > long end = System.nanoTime(); > if ( ( i % SHOWEVERY_xTH_REL == 0 ) || ( end - start > > SHOWINFO_IF_REL_TOOK_MORE_THAN_ns ) ) { > System.out.println( number( i ) + " timeDelta=" + > number( end - start ) ); > } > } > > System.out.println( "counting..." ); > long start = System.nanoTime(); > Iterable<Relationship> rel = one.getRelationships( > Direction.OUTGOING, moo ); > long count = 0; > long tstart = 0; > for ( Relationship relationship : rel ) { > long tend = System.nanoTime(); > count++; > if ( ( tend - tstart > > SHOWINFO_IF_COUNTING_REL_TOOK_MORE_THAN_ns ) ) { > System.out.println( number( count ) + " timeDelta=" + > number( tend - tstart ) ); > } > tstart = System.nanoTime(); > } > long end = System.nanoTime(); > System.out.println( "Node `" + one.getProperty( NAME_KEY ) + "` > has " + number( count ) + " out rels, time=" > + number( end - start ) ); > > // /* > // * (Neo) --> (Trinity) > // * \ ^ > // * v / > // * (Morpheus) --> (Cypher) > // * \ | > // * v v > // * (Agent Smith) > // */ > // createChain( "Neo", "Trinity" ); > // createChain( "Neo", "Morpheus", "Trinity" ); > // createChain( "Morpheus", "Cypher", "Agent Smith" ); > // createChain( "Morpheus", "Agent Smith" ); > tx.success(); > } finally { > long start = System.nanoTime(); > tx.finish(); > long end = System.nanoTime(); > System.out.println( "tx.finish() time=" + number( end - start ) > ); > } > > System.out.println( "counting outside of transaction..." ); > > long start = System.nanoTime(); > Iterable<Relationship> rel = one.getRelationships( > Direction.OUTGOING, moo ); > long count = 0; > for ( Relationship relationship : rel ) { > count++; > > } > long end = System.nanoTime(); > System.out.println( "Node `" + one.getProperty( NAME_KEY ) + "` has > " + number( count ) + " out rels, time=" > + number( end - start ) ); > // So let's find the shortest path between Neo and Agent Smith > // Node neo = getOrCreateNode( "Neo" ); > // Node agentSmith = getOrCreateNode( "Agent Smith" ); > // // START SNIPPET: shortestPathUsage > // PathFinder<Path> finder = GraphAlgoFactory.shortestPath( > Traversal.expanderForTypes( KNOWS, Direction.BOTH ), 4 ); > // Path foundPath = finder.findSinglePath( neo, agentSmith ); > // System.out.println( "Path from Neo to Agent Smith: " + > Traversal.simplePathToString( foundPath, NAME_KEY ) ); > // END SNIPPET: shortestPathUsage > > > // graphDb.shutdown(); > } > > > private static void createChain( String... names ) { > for ( int i = 0; i < names.length - 1; i++ ) { > Node firstNode = getOrCreateNode( names[i] ); > Node secondNode = getOrCreateNode( names[i + 1] ); > firstNode.createRelationshipTo( secondNode, KNOWS ); > } > } > > > private static Node getOrCreateNode( String name ) { > Node node = indexService.get( NAME_KEY, name ).getSingle(); > if ( node == null ) { > System.out.println( "creating new node with name=" + name ); > > node = graphDb.createNode(); > node.setProperty( NAME_KEY, name ); > indexService.add( node, NAME_KEY, name ); > } > return node; > } > > > private static void registerShutdownHook() { > // Registers a shutdown hook for the Neo4j instance so that it > // shuts down nicely when the VM exits (even if you "Ctrl-C" the > // running example before it's completed) > Runtime.getRuntime().addShutdownHook( new Thread() { > > @SuppressWarnings( "synthetic-access" ) > @Override > public void run() { > System.out.println( "Shutting down database ..." ); > graphDb.shutdown(); > } > } ); > } > > > private static void deleteFileOrDirectory( File file ) { > if ( file.exists() ) { > if ( file.isDirectory() ) { > for ( File child : file.listFiles() ) { > deleteFileOrDirectory( child ); > } > } > file.delete(); > } > } > } > > > On Thu, Jul 21, 2011 at 5:01 AM, cyuczi eekc <cyuczie...@gmail.com> wrote: > >> I should probably mention that I am using neo4j community (embedded) >> latest sources up to date from github >> >> >> On Thu, Jul 21, 2011 at 4:59 AM, cyuczi eekc <cyuczie...@gmail.com>wrote: >> >>> Trying to count the relationships "the normal way" I find that oddly, I >>> cannot see more than 100+x relationships, where x is the maximum number of >>> relations ever added within a transaction. >>> For example, if I add 91 relationships in a transation, and I count >>> them, I have 91. I run the program again and I have 182, then I run the >>> program again and I count 191, and any subsequent program runs will have the >>> same 191 count. Is this a bug or am I missing something very important ?! >>> Here's the sample code to try (run it 3 times and observe the >>> ante-ante-last line on console: "Node `one` has 191 out rels, >>> time=24,098,904"): >>> (I don't know how I would place this code into a code block though) >>> >>> /** >>> * Licensed to Neo Technology under one or more contributor >>> * license agreements. See the NOTICE file distributed with >>> * this work for additional information regarding copyright >>> * ownership. Neo Technology licenses this file to you under >>> * the Apache License, Version 2.0 (the "License"); you may >>> * not use this file except in compliance with the License. >>> * You may obtain a copy of the License at >>> * >>> * http://www.apache.org/licenses/LICENSE-2.0 >>> * >>> * Unless required by applicable law or agreed to in writing, >>> * software distributed under the License is distributed on an >>> * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY >>> * KIND, either express or implied. See the License for the >>> * specific language governing permissions and limitations >>> * under the License. >>> */ >>> package org.neo4j.examples; >>> >>> import java.io.*; >>> import java.text.*; >>> >>> import org.neo4j.graphdb.*; >>> import org.neo4j.graphdb.index.*; >>> import org.neo4j.kernel.*; >>> >>> >>> >>> public class CalculateShortestPath { >>> >>> private static final int >>> SHOWINFO_IF_COUNTING_REL_TOOK_MORE_THAN_ns = 2 * 300; >>> private static final int >>> SHOWINFO_IF_REL_TOOK_MORE_THAN_ns = 30000; >>> private static final int SHOWEVERY_xTH_REL >>> = 10000; >>> private static final int HOWMANY_RELATIONSHIPS >>> = 91; >>> private static final String DB_PATH >>> = "neo4j-shortest-path"; >>> private static final String NAME_KEY >>> = "name"; >>> private static RelationshipType KNOWS >>> = DynamicRelationshipType >>> >>> .withName( "KNOWS" ); >>> >>> private static GraphDatabaseService graphDb; >>> private static Index<Node> indexService; >>> private static DecimalFormat commaDelimitedFormatter >>> = new DecimalFormat( "###,###" ); >>> >>> >>> public static String number( double val ) { >>> return commaDelimitedFormatter.format( val ); >>> } >>> >>> >>> public static String getTimeDelta( long start, long end ) { >>> return commaDelimitedFormatter.format( end - start ); >>> } >>> >>> >>> public static void main( final String[] args ) { >>> // deleteFileOrDirectory( new File( DB_PATH ) );// XXX: >>> graphDb = new EmbeddedGraphDatabase( DB_PATH ); >>> indexService = graphDb.index().forNodes( "nodes" ); >>> registerShutdownHook(); >>> Transaction tx = graphDb.beginTx(); >>> try { >>> Node one = getOrCreateNode( "one" ); >>> DynamicRelationshipType moo = >>> DynamicRelationshipType.withName( "moo" ); >>> for ( int i = 1; i <= HOWMANY_RELATIONSHIPS; i++ ) { >>> long start = System.nanoTime(); >>> Relationship rel = one.createRelationshipTo( >>> graphDb.createNode(), moo ); >>> rel.setProperty( "relname", i ); >>> long end = System.nanoTime(); >>> if ( ( i % SHOWEVERY_xTH_REL == 0 ) || ( end - start > >>> SHOWINFO_IF_REL_TOOK_MORE_THAN_ns ) ) { >>> System.out.println( number( i ) + " timeDelta=" + >>> number( end - start ) ); >>> } >>> } >>> >>> System.out.println( "counting..." ); >>> long start = System.nanoTime(); >>> Iterable<Relationship> rel = one.getRelationships( >>> Direction.OUTGOING, moo ); >>> long count = 0; >>> long tstart = 0; >>> for ( Relationship relationship : rel ) { >>> long tend = System.nanoTime(); >>> count++; >>> if ( ( tend - tstart > >>> SHOWINFO_IF_COUNTING_REL_TOOK_MORE_THAN_ns ) ) { >>> System.out.println( number( count ) + " timeDelta=" + >>> number( tend - tstart ) ); >>> } >>> tstart = System.nanoTime(); >>> } >>> long end = System.nanoTime(); >>> System.out.println( "Node `" + one.getProperty( NAME_KEY ) + >>> "` has " + number( count ) + " out rels, time=" >>> + number( end - start ) ); >>> >>> // /* >>> // * (Neo) --> (Trinity) >>> // * \ ^ >>> // * v / >>> // * (Morpheus) --> (Cypher) >>> // * \ | >>> // * v v >>> // * (Agent Smith) >>> // */ >>> // createChain( "Neo", "Trinity" ); >>> // createChain( "Neo", "Morpheus", "Trinity" ); >>> // createChain( "Morpheus", "Cypher", "Agent Smith" ); >>> // createChain( "Morpheus", "Agent Smith" ); >>> tx.success(); >>> } finally { >>> long start = System.nanoTime(); >>> tx.finish(); >>> long end = System.nanoTime(); >>> System.out.println( "tx.finish() time=" + number( end - start >>> ) ); >>> } >>> >>> // So let's find the shortest path between Neo and Agent Smith >>> // Node neo = getOrCreateNode( "Neo" ); >>> // Node agentSmith = getOrCreateNode( "Agent Smith" ); >>> // // START SNIPPET: shortestPathUsage >>> // PathFinder<Path> finder = GraphAlgoFactory.shortestPath( >>> Traversal.expanderForTypes( KNOWS, Direction.BOTH ), 4 ); >>> // Path foundPath = finder.findSinglePath( neo, agentSmith ); >>> // System.out.println( "Path from Neo to Agent Smith: " + >>> Traversal.simplePathToString( foundPath, NAME_KEY ) ); >>> // END SNIPPET: shortestPathUsage >>> >>> >>> // graphDb.shutdown(); >>> } >>> >>> >>> private static void createChain( String... names ) { >>> for ( int i = 0; i < names.length - 1; i++ ) { >>> Node firstNode = getOrCreateNode( names[i] ); >>> Node secondNode = getOrCreateNode( names[i + 1] ); >>> firstNode.createRelationshipTo( secondNode, KNOWS ); >>> } >>> } >>> >>> >>> private static Node getOrCreateNode( String name ) { >>> Node node = indexService.get( NAME_KEY, name ).getSingle(); >>> if ( node == null ) { >>> node = graphDb.createNode(); >>> node.setProperty( NAME_KEY, name ); >>> indexService.add( node, NAME_KEY, name ); >>> } >>> return node; >>> } >>> >>> >>> private static void registerShutdownHook() { >>> // Registers a shutdown hook for the Neo4j instance so that it >>> // shuts down nicely when the VM exits (even if you "Ctrl-C" the >>> // running example before it's completed) >>> Runtime.getRuntime().addShutdownHook( new Thread() { >>> >>> @SuppressWarnings( "synthetic-access" ) >>> @Override >>> public void run() { >>> System.out.println( "Shutting down database ..." ); >>> graphDb.shutdown(); >>> } >>> } ); >>> } >>> >>> >>> private static void deleteFileOrDirectory( File file ) { >>> if ( file.exists() ) { >>> if ( file.isDirectory() ) { >>> for ( File child : file.listFiles() ) { >>> deleteFileOrDirectory( child ); >>> } >>> } >>> file.delete(); >>> >>> } >>> } >>> } >>> >>> >>> >>> On Thu, Jul 21, 2011 at 3:39 AM, Michael Hunger < >>> michael.hun...@neotechnology.com> wrote: >>> >>>> Caching that result would require synchronizing it with every change >>>> using up memory and performance (at every change) for something that can be >>>> computed >>>> >>>> So far it has not been worth the effort. >>>> >>>> If you really need that value very often you could write a small >>>> TransactionEventHandler that keeps the count updated for the nodes you're >>>> interested in. You would then >>>> ask this handler for the Rel-Count of a node, which would either compute >>>> it (and add/register it to its cache) or just return it from the cache. >>>> >>>> Michael >>>> >>>> Am 20.07.2011 um 21:50 schrieb cyuczi eekc: >>>> >>>> > I guess I was hoping it(size/count) was cached in the database or the >>>> > underlaying database would provide this somehow, ie. in berkeleydb >>>> (java >>>> > edition) there's a cursor.count() I could use (though I don't know how >>>> they >>>> > did it implementation-wise) >>>> > >>>> > Thanks! I needed to know that. >>>> > >>>> > On Wed, Jul 20, 2011 at 8:37 PM, Jim Webber <j...@neotechnology.com> >>>> wrote: >>>> > >>>> >> Hi, >>>> >> >>>> >> Responses from calling the Neo4j APIs are typically lazy, for >>>> performance >>>> >> reasons. So there's no way of eagerly counting the number of >>>> relationships >>>> >> unless you force eager evaluation as you've suggested below. >>>> >> >>>> >> Jim >>>> >> >>>> >> On 20 Jul 2011, at 11:13, cyuczi eekc wrote: >>>> >> >>>> >>> Is there a way to get the number of relationships without having to >>>> >> iterate >>>> >>> through (and count++) them? >>>> >>> ie. rels=firstNode.getRelationships(); >>>> >>> rels.size(); //doesn't actually exist >>>> >>> _______________________________________________ >>>> >>> Neo4j mailing list >>>> >>> User@lists.neo4j.org >>>> >>> https://lists.neo4j.org/mailman/listinfo/user >>>> >> >>>> >> _______________________________________________ >>>> >> Neo4j mailing list >>>> >> User@lists.neo4j.org >>>> >> https://lists.neo4j.org/mailman/listinfo/user >>>> >> >>>> > _______________________________________________ >>>> > Neo4j mailing list >>>> > User@lists.neo4j.org >>>> > https://lists.neo4j.org/mailman/listinfo/user >>>> >>>> _______________________________________________ >>>> Neo4j mailing list >>>> User@lists.neo4j.org >>>> https://lists.neo4j.org/mailman/listinfo/user >>>> >>> >>> >> > _______________________________________________ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
