1. They are "durable" but not "permanent", in the sense that if a node is deleted, its ID will be re-used, unlike autoincremented keys in a database, which are typically not re-used. Perhaps a poor choice of words.
2. Totally agree regarding a "full delete" method. We're big kids, we can decide if we want to take the risk. ;-) 3. Third parameter = value of the K-V pair you're using to index the node. 4. The reference node is merely one approach to a graph structure. You can have any number of standalone nodes. Reasonable to allow deleting the default reference node, though it might be a good idea to make this a configurable option on DB creation. 5/6. Haven't done much with Lucene yet, about to get started soon. Please keep sharing your experiences. Considering whether or not to use SOLR, also. -------- Original Message -------- Subject: [Neo4j] API Questions and a bit more From: Alexandru_Popescu_� <[1][email protected]> Date: Fri, September 03, 2010 4:53 am To: [2][email protected] Hi all, Last night I had some time to play with Neo4j (1.1) API. I do have a couple of questions and comments that I'd like to share with you: 1. The documentation I've found mentions that `Node` IDs are not "permanent". I'm wondering why are IDs exposed them? 2. I was surprised to see a `Node`.delete() failing. The reason was it had relationships. I think adding a method `Node`.delete(boolean force) would make code much easier. The method would automatically: - remove all relationships - clean up indexes Note 1: I've been able to implement locally such a method in an utility class and it seems to work without any problems. Anyways another thing that I've found a bit weird was that I had to use separate reference to GraphDatabaseService and 2 IndexServices (a simple LuceneIndexService and a LuceneFulltextIndexService). I think it would once again simplify a lot of things if these IndexServices would be available through the GraphDatabaseService API. Note 2: as far as I can say this would be a non-breaking API change 3. I was a bit confused when trying to index a new node as I wasn't sure what's the last parameter in `IndexService.index(Node, String, Object)`. While understanding the flexibility this would offer, I'd speculate that most of the time you'd want to actually index the values set in the Node, so an API like `IndexService.index(Node, String... properties)` would once again simplify a lot of code. Note: as far as I can say this is a non-breaking API change 4. Q: while running my tests, I've tried to clean up data behind. Thus I've discovered that I can delete the so called "reference node". That made me wonder: if it is a default node, why allowing to be deleted? 5. Q: by looking at the documentation I couldn't figure out for sure if you are allowed to use both a LuceneIndexService and LuceneFullIndexService. My tests seem to work while using both, but I'm not sure if that is what's suppose to happen. 6. I've run into a test where LuceneFullIndexService doesn't seem to return what I'm expecting. But I'm not a Lucene specialist so maybe I'm doing something wrong. Code below: package com.mypopescu.neo4j; import org.junit.AfterClass; import org.junit.BeforeClass; import org.junit.Test; import org.neo4j.graphdb.GraphDatabaseService; import org.neo4j.graphdb.Node; import org.neo4j.graphdb.Relationship; import org.neo4j.graphdb.Transaction; import org.neo4j.index.IndexHits; import org.neo4j.index.IndexService; import org.neo4j.index.lucene.LuceneFulltextIndexService; import org.neo4j.kernel.EmbeddedGraphDatabase; import [3]java.io.File; import static [4]org.hamcrest.CoreMatchers.is; import static org.junit.Assert.assertThat; /** * @author Alex Popescu * @since Sep 3, 2010 */ public class LuceneFulltextIndexServiceTest { static GraphDatabaseService gds; static IndexService fulltextIndex; @BeforeClass public static void setup() { gds= new EmbeddedGraphDatabase("data/neodb/neodb-tmp"); fulltextIndex= new LuceneFulltextIndexService(gds); } @Test public void fullTextIndex() { Transaction tx= gds.beginTx(); try { Node ndOne= gds.createNode(); ndOne.setProperty("ft", "some text in here to be fully indexed"); fulltextIndex.index(ndOne, "ft", ndOne.getProperty("ft")); Node ndTwo= gds.createNode(); ndTwo.setProperty("ft", "some other text in there not to be indexed uniquely"); fulltextIndex.index(ndTwo, "ft", ndTwo.getProperty("ft")); tx.success(); } finally { tx.finish(); } IndexHits<Node> ns= fulltextIndex.getNodes("ft", "some text"); assertThat(ns.size(), is(2)); for(Node n : ns) { System.out.printf("Full text n...@%s: {%s}%n", n.getId(), n.getProperty("ft")); } ns= fulltextIndex.getNodes("ft", "some text indexed"); assertThat(ns.size(), is(2)); for(Node n : ns) { System.out.printf("Full text n...@%s: {%s}%n", n.getId(), n.getProperty("ft")); } ns= fulltextIndex.getNodes("ft", "indexed text"); assertThat(ns.size(), is(2)); for(Node n : ns) { System.out.printf("Full text n...@%s: {%s}%n", n.getId(), n.getProperty("ft")); } ns= fulltextIndex.getNodes("ft", "uniquely text"); assertThat(ns.size(), is(1)); for(Node n : ns) { System.out.printf("Full text n...@%s: {%s}%n", n.getId(), n.getProperty("ft")); } // THIS ONE IS FAILING ns= fulltextIndex.getNodes("ft", "uniquely OR text"); assertThat("actually it should find 2", ns.size(), is(2)); for(Node n : ns) { System.out.printf("Full text n...@%s: {%s}", n.getId(), n.getProperty("ft")); } } @AfterClass public static void shutdown() { fulltextIndex.shutdown(); gds.shutdown(); } } 7. I was wondering what is the best way to clean up a temporary test database. My apologies in advance for such a long email (I usually don't do this). And thanks in advance for all your answers, :- alex _______________________________________________ Neo4j mailing list [5][email protected] [6]https://lists.neo4j.org/mailman/listinfo/user References 1. mailto:[email protected] 2. mailto:[email protected] 3. http://java.io/ 4. http://org.hamcrest.CoreMatchers.is/ 5. mailto:[email protected] 6. https://lists.neo4j.org/mailman/listinfo/user
_______________________________________________ Neo4j mailing list [email protected] https://lists.neo4j.org/mailman/listinfo/user
