Hi Todd,
I am not sure if I understand your problem correctly. I am not familiar with
Lucandra/Cassandra at all, but if Lucandra implements the IndexWriter and
IndexReader according to the documentation, numeric queries should work. A
NumericField internally creates a TokenStream and "analyzes" the number to
several Tokens, which are somehow "half binary" (they are terms containing of
characters in the full 0..127 range for optimal UTF8 compression with 3.x
versions of Lucene). The exact encoding can be looked at in the NumericUtils
class + javadocs.
About your testcase: The test looks good, so does it fail? If yes, where is the
problem? You can also look into Lucene's test TestNumericRangeQuery64 for more
examples. Or modify its @BeforeClass to instead build a Lucandra index.
The test has one thing, that is not intended to be done like that:
numeric = new NumericField("long", Integer.MAX_VALUE, Store.YES, true);
You are using MAX_VALUE as precision step, this would slowdown all queries to
the speed of old-style TermRangeQueries. It is always better to stick with the
default of 4, which creates 64 bits / 4 precStep = 16 terms per value.
Alternatively for longs, 6 is a good precision step (see NumericRangeQuery
documentation). MAX_VALUE is only intended for fields that do not do numeric
ranges but e.g. sort only. precisionStep is a performance tuning parameter, it
has nothing to do with better/worse precision on terms or different query
results. If you are using NumericRangeQuery with this large precStep, you are
not using the numeric features at all, so your test should not behave different
from a conventional TermRangeQuery with padded terms.
Uwe
-----
Uwe Schindler
H.-H.-Meier-Allee 63, D-28213 Bremen
http://www.thetaphi.de
eMail: u...@thetaphi.de
> -----Original Message-----
> From: Todd Nine [mailto:t...@spidertracks.co.nz]
> Sent: Wednesday, June 23, 2010 7:53 AM
> To: java-user@lucene.apache.org
> Subject: Help with Numeric Range
>
> Hi all,
> I'm new to Lucene, as well as Cassandra. I'm working on the Lucandra
> project to modify it to add some extra functionality. It hasn't been fully
> testing with range queries, so I've created some tests and contributed them.
> You can view my source here.
>
> http://github.com/tnine/Lucandra/blob/master/test/lucandra/NumericRang
> eTests.java
>
> First, is this a sensible test? I'm specifically testing the case of longs
> where I
> need millisecond precision on my searches.
>
>
> Second, I see that Numeric Fields are built via terms. I think the issue
> lies in
> the encoding of these terms into bytes for the Cassandra keys. Can anyone
> point me to some documentation on numeric queries and terms, and how
> they are encoded at the byte level based on the precision?
>
> Thanks,
> Todd
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