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Michael Dürig commented on JCR-2906:
------------------------------------

Ok works now: all core tests pass. 

Do we know about the impact on query performance? All this array creation and compacting. It seems to me this might happen quite a lot for nodes with a lot of indexed properties. 
                
> Multivalued property sorted by last/random value
> ------------------------------------------------
>
>                 Key: JCR-2906
>                 URL: https://issues.apache.org/jira/browse/JCR-2906
>             Project: Jackrabbit Content Repository
>          Issue Type: Improvement
>          Components: indexing
>    Affects Versions: 2.2
>         Environment: Windows 7, Sun JDK 1.6.0_23
>            Reporter: Paul Lysak
>              Labels: multivalued, sort
>         Attachments: JCR-2906-SharedFieldCache.patch, JCR-2906-v2.patch, JCR-2906.patch
>
>
> Sorting on multivalued property may produce incorrect result because sorting is performed only by last value of multivalued property.
> Steps to reproduce:
> 1. Create multivalued field in repository. Example from nodetypes file:
> <propertyDefinition name="MyProperty" requiredType="String" autoCreated="false" mandatory="false"
>    onParentVersion="COPY" protected="false" multiple="false">
> 2. Create few records so that all records except one would contain single value for MyProperty and one record would contain 
> first value which is greater then of any other record and the second value is somewhere in the middle. Here is an example:
> 1st record: "aaaa"
> 2nd record: "cccc"
> 3rd record: "dddd", "bbbb"
> 3. Run some query which sorts Example of XPath query:
> //*[...here are some criteria...] order by @MyProperty ascending
> The query would return documents in such order:
> "aaaa"
> "dddd", "bbbb"
> "cccc"
> which is not expected order (expected same order as they were entered - as "aaaa" < "cccc", "cccc" < "dddd")
> After some digging I found out that it happens because method 
> org.apache.jackrabbit.core.query.lucene.SharedFieldCache.getValueIndex
> (called from org.apache.jackrabbit.core.query.lucene.SharedFieldSortComparator.SimpleScoreDocComparator constructor)
> returns only last Comparable of the document. Here is overwrites previous value:
> retArray[termDocs.doc()] = getValue(value, type);
> I tried to concatenate comparables (just to check if it would work for my case):
> 	if(retArray[termDocs.doc()] == null) {
> 		retArray[termDocs.doc()] = getValue(value, type);
> 	} else {
> 		retArray[termDocs.doc()] =
> 				retArray[termDocs.doc()] + " " + getValue(value, type);
> 	}
> But it didn't worked well either - TermEnum returns terms not in the same order as JackRabbit returns values of multivalued field
> (as an example ["qwer", "asdf"] may become ["asdf", "qwer"] ). So, simple concatenation doesn't help.

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