# Locate Duplicate Documents

You can locate duplicate documents in the data index after indexing has taken place by using the `DREDUPLICATE` index action. This action locates duplicates in a specified subset of the content, and then removes them, tags a field, or moves the duplicate documents to another database.

    http://ContentHost:indexPort/DREDUPLICATE?ReferenceField=Field&DuplicateAction=Action

where:

`ContentHost` | is the IP address or host name of the machine on which the IDOL Content component is installed.
`indexPort` | is the IDOL Content component index port (specified as `IndexPort` in the `[Server]` section of the IDOL Content component configuration file).
`Field` | is a `ReferenceType` field used as the initial determination of whether two documents are a match.
`Action` | is the action to perform on a duplicate. The following options are available: `Delete`. Deletes all duplicate documents. `Database`. Moves all duplicate documents to a database. If you select the `Database` action, you must specify the database in the `Database` parameter. `Tag`. Tags a specified field in the duplicate document. You must specify the field in the `TagField` index parameter. You can also specify a value to tag the field with by using the `TagValue` parameter. If you do not specify a `TagValue`, the field is tagged with the value `1`.

For example:

    http://MyHost:20001/DREDUPLICATE?ReferenceField=DOCUMENT/DREREFERENCE&DuplicateAction=Database&Database=Duplicates

This action uses port `20001` to remove duplicates from the IDOL Content component that is located on the machine with the host name `MyHost`. Content uses the `DREREFERENCE` field to identify duplicate documents, and moves them to the `Duplicates` database.

    http://MyHost:20001/DREDUPLICATE?ReferenceField=DOCUMENT/DREREFERENCE&DuplicateAction=Tag&TagField=DOCUMENT/DRETITLE&TagValue=Duplicate

In this example, Content initially uses the `DREREFERENCE` field to identify the duplicate documents, and then it changes the `DRETITLE` field to the value `Duplicate`.

To prevent Content from indexing duplicate documents, use the `KillDuplicates` parameter with the `DREADD` and `DREADDDATA` index actions.

For details on the other parameters that are available for the `DREDUPLICATE` index action, refer to the IDOL Server Reference.

Related Topics

- Display Online Help

- Prevent Duplicate Documents

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