Reading the source is always a good thing :)
I don't see them changing in the near future, and even if it's a bit of a
hack to use them (since they are there mostly to be able to remove stuff)
I've used them also in at least one scenario. I think you can give it a go,
but it's not an "official" feature that could potentially change.
2011/6/29 Balazs E. Pataki <pat...@dsd.sztaki.hu>
> Great, thank you!
>
> Another thing I just found in IndexType: for a fulltext index each field
> is stored as fulltext (tokenized into terms) and there's also an "exact"
> field (the same index postfixed with "_e"). I think this feature is not
> documented officially, so my question is, whether we can count on these
> "_e" fields to exist in the lucene index in future versions of neo4j as
> well? Because I would be glad to use it.
>
> In my application I have text content which I index in a "fulltext"
> neo4j/lucene index, but I also have to store it in "exact" form. Without
> knowing about this "_e" feature I had to do this "exact" indexing by
> tweaking the content (replacing spaces with "_" and doing the same with
> search terms). If I could instead depend on "_e" fields, I could get rid
> of my own exact index tweaking and my index would be half as big.
>
> Do you think I can safely depend on these implicit exact indexed fields
> in fulletxt indexes?
>
> Regards,
> ---
> balazs
>
> On 6/29/11 7:44 AM, Mattias Persson wrote:
> > Wow, thank you for finding that. Well done!
> >
> > I'll fix it and if it doesn't break anything else then I'll commit it.
> >
> > Best,
> > Mattias
> >
> > Den tisdagen den 28:e juni 2011 skrev Balazs E. Pataki<
> pat...@dsd.sztaki.hu>:
> >> Hi Mattias,
> >>
> >> Thanks for the tip!
> >>
> >> I started to look around and I think I found something. When "fulltext"
> >> type index is created its type will be CustomType (subclass of IndexType
> >> - IndexType is used for "exact" indexes) in neo4j. CustomType overrides
> >> the addToDocument() of IndexType method, which is the function that
> >> actually created a Lucene field.
> >>
> >> IndexType's looks like this:
> >>
> >> public void addToDocument( Document document, String key, Object value )
> >> {
> >> document.add( instantiateField( key, value, Index.NOT_ANALYZED ) );
> >> }
> >>
> >> CustomType's implementation on teh other hand:
> >>
> >> @Override
> >> public void addToDocument( Document document, String key, Object value )
> >> {
> >> document.add( new Field( exactKey( key ), value.toString(),
> >> Store.YES, Index.NOT_ANALYZED ) );
> >> document.add( instantiateField( key, value.toString(),
> Index.ANALYZED
> >> ) );
> >> }
> >>
> >> What I can see here is that CustomType's version explicitely converts
> >> value to a String and therefore instantiateField won't detect it as a
> >> number and will not create a NumericField for it.
> >>
> >> Could this be the root of the problem?
> >>
> >> I just replaced 'value.toString()' with 'value', and now my test runs OK
> >> (and fulltext search for terms still work beside numeric range queries).
> >>
> >> Regards,
> >> ---
> >> balazs
> >>
> >> On 6/28/11 4:41 PM, Mattias Persson wrote:
> >>> Hi Balazs,
> >>>
> >>> I think the issue could be in lucene, with the mix of the
> >>> white-space-tokenizing-analyzer and numeric values. I don't know. What
> I see
> >>> in neo4j is that it treats the values the exact same way, the queries
> to the
> >>> index is exactly the same, but it just doesn't return any values. I
> think
> >>> there needs to be some more googling around this to get more answers.
> >>>
> >>>
> >>> 2011/6/28 Balazs E. Pataki<pat...@dsd.sztaki.hu>
> >>>
> >>>> Hi,
> >>>>
> >>>> I'm playing around with indexing and numeric range queries according
> to
> >>>> this documentation:
> >>>>
> >>>>
> http://docs.neo4j.org/chunked/snapshot/indexing-lucene-extras.html
> >>>>
> >>>> According to my tests numeric range queries
> >>>> (QueryContext.numericRange()) only have effect when "exact" type index
> >>>> is used.
> >>>>
> >>>>
> >>>> I tried this:
> >>>>
> >>>> Transaction tx = graphDb.beginTx();
> >>>> try {
> >>>>
> >>>> Index<Node> exactIndex = graphDb.index().forNodes("exactIndex",
> >>>> MapUtil.stringMap( IndexManager.PROVIDER, "lucene", "type", "exact"
> ));
> >>>> Index<Node> fulltextIndex =
> graphDb.index().forNodes("fulltextIndex",
> >>>> MapUtil.stringMap( IndexManager.PROVIDER, "lucene", "type", "fulltext"
> ));
> >>>>
> >>>> Node n1 = graphDb.createNode();
> >>>> n1.setProperty("foo", 5);
> >>>> exactIndex.add(n1, "foo", ValueContext.numeric(5));
> >>>> fulltextIndex.add(n1, "foo", ValueContext.numeric(5));
> >>>>
> >>>> Node n2 = graphDb.createNode();
> >>>> n2.setProperty("foo", 25);
> >>>> exactIndex.add(n2, "foo", ValueContext.numeric(25));
> >>>> fulltextIndex.add(n2, "foo", ValueContext.numeric(25));
> >>>>
> >>>> // Force commit
> >>>> tx.success();
> >>>> tx.finish();
> >>>> tx = graphDb.beginTx();
> >>>>
> >>>> //Search exact
> >>>> QueryContext qctx = QueryContext.numericRange("foo", 3, 25);
> >>>> IndexHits<Node> hits = exactIndex.query(qctx);
> >>>> Iterator<Node> it = hits.iterator();
> >>>> while (it.hasNext()) {
> >>>> Node n = it.next();
> >>>> System.out.println("Found foo in exact: "+n+":
> >>>> "+n.getProperty("foo"));
> >>>> }
> >>>> assertEquals(2, hits.size());
> >>>>
> >>>> //Search fulltext
> >>>> qctx = QueryContext.numericRange("foo", 3, 25);
> >>>> hits = fulltextIndex.query(qctx);
> >>>> it = hits.iterator();
> >>>> while (it.hasNext()) {
> >>>> Node n = it.next();
> >>>> System.out.println("Found foo in fulltext: "+n+":
> >>>> "+n.getProperty("foo"));
> >>>> }
> >>>> assertEquals(2, hits.size());
> >>>>
> >>>> tx.success();
> >>>> } finally {
> >>>> tx.finish();
> >>>> }
> >>>>
> >>>> For the "exact" configured index the range query returns two nodes,
> >>>> while in "fulltext" configured index I get no result.
> >>>>
> >>>> Is there a way to use numeric range queries with fulltext indexes?
> >>>>
> >>>> Thanks for any hints,
> >>>> ---
> >>>> balazs
> >>>> _______________________________________________
> >>>> Neo4j mailing list
> >>>> User@lists.neo4j.org
> >>>> https://lists.neo4j.org/mailman/listinfo/user
> >>>>
> >>>
> >>>
> >>>
> >> _______________________________________________
> >> Neo4j mailing list
> >>
> >
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>
--
Mattias Persson, [matt...@neotechnology.com]
Hacker, Neo Technology
www.neotechnology.com
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