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Subject: RE: Getting started
Date: Fri, 15 May 2009 12:06:37 -0400
Message-ID: 
 <2D397C4478FC2844B46F929D1ADEB2C103BFC856@mid1w2smail1.na1.vis.verizon.com>
In-Reply-To: <e2e029610905140829m3a9fc84chcdd537901a614fb8@mail.gmail.com>
Thread-Topic: Getting started
Thread-index: AcnUshub2uawp9ruSLybmlea2h8AYQAw+F9w
References: 
 <2D397C4478FC2844B46F929D1ADEB2C103BFC78C@mid1w2smail1.na1.vis.verizon.com>
 <e2e029610905140829m3a9fc84chcdd537901a614fb8@mail.gmail.com>
From: "Burnett, Adam" <Adam.Burnett@idearc.com>
To: "Sean Owen" <srowen@gmail.com>,
	<mahout-user@lucene.apache.org>

I'm running into another stack trace once I switched to using an =
OracleDataSource.  AbstractJDBCDataModel is setting the fetch direction =
to FETCH_UNKNOWN which causes the ResultSet.isLast() call to fail. I =
think using TYPE_SCROLL_INSENSITIVE as the direction should resolve this =
issue.  Do you think it makes sense to change this in the abstract data =
model class or is this a special case that requires a custom =
OracleJDBCDataModel?

Here's the trace:
java.sql.SQLException: Invalid operation for forward only resultset : =
isLast
	at =
oracle.jdbc.driver.SQLStateMapping.newSQLException(SQLStateMapping.java:7=
0)
	at =
oracle.jdbc.driver.DatabaseError.newSQLException(DatabaseError.java:131)
	at =
oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:197=
)
	at =
oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:261=
)
	at =
oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:269=
)
	at =
oracle.jdbc.driver.OracleResultSetImpl.isLast(OracleResultSetImpl.java:36=
8)
	at =
org.apache.mahout.cf.taste.impl.model.jdbc.AbstractJDBCDataModel$ResultSe=
tUserIterator.hasNext(AbstractJDBCDataModel.java:577)
	at =
org.apache.mahout.cf.taste.impl.recommender.TopItems.getTopUsers(TopItems=
.java:81)
	at =
org.apache.mahout.cf.taste.impl.neighborhood.NearestNUserNeighborhood.get=
UserNeighborhood(NearestNUserNeighborhood.java:102)
	at =
org.apache.mahout.cf.taste.impl.recommender.GenericUserBasedRecommender.r=
ecommend(GenericUserBasedRecommender.java:83)
	at =
org.apache.mahout.cf.taste.impl.recommender.AbstractRecommender.recommend=
(AbstractRecommender.java:53)
	at =
org.apache.mahout.cf.taste.impl.recommender.CachingRecommender$Recommenda=
tionRetriever.get(CachingRecommender.java:198)
	at =
org.apache.mahout.cf.taste.impl.recommender.CachingRecommender$Recommenda=
tionRetriever.get(CachingRecommender.java:185)
	at =
org.apache.mahout.cf.taste.impl.common.Cache.getAndCacheValue(Cache.java:=
103)
	at org.apache.mahout.cf.taste.impl.common.Cache.get(Cache.java:77)
	at =
org.apache.mahout.cf.taste.impl.recommender.CachingRecommender.recommend(=
CachingRecommender.java:123)
	at =
org.apache.mahout.cf.taste.impl.recommender.CachingRecommender.recommend(=
CachingRecommender.java:99)


-Adam=20


-Adam

-----Original Message-----
From: Sean Owen [mailto:srowen@gmail.com]=20
Sent: Thursday, May 14, 2009 11:29 AM
To: mahout-user@lucene.apache.org; Burnett, Adam
Subject: Re: Getting started

That's my bad. I just committed a fix that makes the result of these
methods in RandomUtils more reasonable for small values and should fix
this corner-ish case.

The org.apache.mahout.cf.taste stuff itself does not require Hadoop;
the Hadoop bindings are all in org.apache.mahout.cf.taste.hadoop.

2009/5/14 Burnett, Adam <Adam.Burnett@idearc.com>:
> Hello Mahout community. =A0I'm just getting started in exploring how =
to
> integrate Mahout into my application. I've written a quick sample but
> I'm getting the following exception when trying to use the
> SlopeOneRecommender.
>
> INFO: Building average diffs...
> Exception in thread "main" java.lang.IllegalArgumentException
> =A0 =A0 =A0 =A0at
> =
org.apache.mahout.cf.taste.impl.common.RandomUtils.isNotPrime(RandomUtil
> s.java:93)
> =A0 =A0 =A0 =A0at
> =
org.apache.mahout.cf.taste.impl.common.RandomUtils.nextPrime(RandomUtils
> .java:81)
> =A0 =A0 =A0 =A0at
> =
org.apache.mahout.cf.taste.impl.common.RandomUtils.nextTwinPrime(RandomU
> tils.java:67)
> =A0 =A0 =A0 =A0at
> =
org.apache.mahout.cf.taste.impl.common.FastMap.rehash(FastMap.java:285)
> =A0 =A0 =A0 =A0at
> =
org.apache.mahout.cf.taste.impl.recommender.slopeone.MemoryDiffStorage.p
> runeInconsequentialDiffs(MemoryDiffStorage.java:254)
> =A0 =A0 =A0 =A0at
> =
org.apache.mahout.cf.taste.impl.recommender.slopeone.MemoryDiffStorage.b
> uildAverageDiffs(MemoryDiffStorage.java:227)
> =A0 =A0 =A0 =A0at
> =
org.apache.mahout.cf.taste.impl.recommender.slopeone.MemoryDiffStorage.<
> init>(MemoryDiffStorage.java:119)
> =A0 =A0 =A0 =A0at
> =
org.apache.mahout.cf.taste.impl.recommender.slopeone.SlopeOneRecommender
> .<init>(SlopeOneRecommender.java:65)
>
> I built Mahout from the 774566 revision of the trunk. =A0I have a
> MySQLJDBCDataModel that reads a custom table from my database. =A0One
> question I have is do I have to have the hadoop cluster running before
> attempting to use Mahout in my app? =A0Could not having it running =
cause
> the above error? =A0Any thoughts in how to proceed from here? =
=A0Thanks!
>
> Adam Burnett
>
>
>