Distributed Index Handler 26.1
Distributed Index Handler Help

# Date-Based Indexing

You can use date-based indexing to distribute the indexing load between child servers. Date-based indexing uses the date of the documents being indexed or in which you replace fields.

When you enable date-based indexing, DIH indexes each document in a DREADD and DREADDDATA action by its `#DREDATE` field, or another DateType field configured in the `[FieldProcessing]` section. It indexes each replace in a DREREPLACE action based on its `#DREDATE` line, if it exists. Otherwise it sends the action to all child servers. It sends all other actions to all child servers.

When you use date-based indexing, you cannot alter the number of child servers.

To enable date-based indexing, set DistributeByDate to `True` in the `[Server]` section of the DIH configuration file.

Configure the date ranges for child servers by using a `[DateRangeN]` subsection in the `[DistributionIDOLServers]` section of the DIH configuration file.

For both DIH stand-alone and unified configuration, you must configure DateFormatCSVs in the `[Server]` section for date-based indexing to work. For example:

    [Server]
    Port=9070
    DIHPort=9071
    MirrorMode=False
    DistributeByDate=True
    DateFormatCSVs=DD/MM/YYYY,YYYY/MM/DD,YYYY-MM-DD

    [DistributionIDOLServers]
    Number=2

    [IDOLServer0]
    Host=localhost
    Port=9100

    [IDOLServer1]
    Host=localhost
    Port=9500

    [DateRange0]
    FromDate=1980/01/01
    UpToDate=1990/01/01
    Engines=0

    [DateRange1]
    FromRelative=-3
    UpToRelative=5
    Engines=1

In this example, server 0 indexes documents dated from 1 January 1980 to 31 December 1989. If it is Tuesday (relative 0), server 1 gets documents dated from the previous Saturday (relative -3) and from the following Saturday (relative 4). The upper limit is exclusive.

NOTE: You can use DistributeByDate only when MirrorMode is set to `False`. DIH will not start if DistributeByDate and MirrorMode are both set to `True`.

In DistributeByDate mode, you can also use the UnknownFieldValueAction configuration parameter to determine how to treat documents where the date field is missing, contains a value that DIH cannot parse as a date, or contains a date value that does not match the configured date ranges. For more information, refer to the DIH Reference.

Copyright 2025 Open Text
Version 26.1 | Last updated January 2026

Send documentation feedback

Close

Send documentation feedback

To send feedback using your default email client, open an email window.

Otherwise, send your feedback and the information below to MFI-swpdl.idoldocsfeedback@opentext.com.

We appreciate your feedback!

Product: Knowledge Discovery Distributed Index Handler 26.1

Topic Title: Date-Based Indexing