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Date: Mon, 20 Jun 2011 14:13:04 +0100
From: Paolo Castagna <castagna.lists@googlemail.com>
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To: jena-dev@incubator.apache.org
Subject: Re: Literal Canonicalization
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Hi Ian.

The existing documentation on this is here:

  - http://www.openjena.org/wiki/TDB/ValueCanonicalization

The code, here:
http://svn.apache.org/repos/asf/incubator/jena/Jena2/TDB/trunk/src/main/java/com/hp/hpl/jena/tdb/store/NodeId.java

See these two methods:

  - public static NodeId inline(Node node)
  - public static Node extract(NodeId nodeId)

See also:

  - DateTimeNode.java
  - IntegerNode.java
  - DecimalNode.java

I hope this helps,
Paolo

Ian Emmons wrote:
> I recall reading some time ago that TDB transforms literals (and particularly their data types) into a canonical form upon insert, and/or that it can "promote" literal datatypes during comparisons (so that, e.g., an xsd:int and an xsd:long can compare equal).  Is there any documentation on this?  Or failing that, can you point me to the appropriate portion of the code?
> 
> Thanks,
> 
> Ian Emmons
> BBN Technologies