Solr: delta-import, help needed

[Giovanni De Stefano]

Hello all,

I have a table TEST in an Oracle DB with the following columns: URI
(varchar), CONTENT (varchar), CREATION_TIME (date).

The primary key both in the DB and Solr is URI.

Here is my data-config.xml:

<dataConfig>
  <dataSource
    driver="oracle.jdbc.driver.OracleDriver"
    url="jdbc:oracle:thin:@localhost:1521/XE"
    user="username"
    password="password"
  />
  <document name="Test">
    <entity
        name="test_item"
        pk="URI"
        query="select URI,CONTENT from TEST"
*        deltaQuery="select URI,CONTENT from TEST where
TO_CHAR(CREATION_TIME,'YYYY-MM-DD HH:MI:SS') >
'${dataimporter.last_index_time}'" *
    >
      <field column="URI" name="uri"/>
      <field column="CONTENT" name="content"/>
    </entity>
  </document>
</dataConfig>

The problem is that anytime I perform a delta-import, the index keeps being
populated as if new documents were added. In other words, I am not able to
UPDATE an existing document or REMOVE a document that is not anymore in the
DB.

What am I missing? How should I specify my deltaQuery?

Thanks a lot in advance!

Giovanni