1. Use dsconfig to set attribute indexing on an attribute in the Changelog Backend.
    The following command enables the Changelog Backend and sets the backend to include all user attributes ("*") for ADD or MODIFY operations using the changelog-include-attribute property. The changelog-deleted-entry-include-attribute property is set to all attributes ("*") to specify a set of attribute types that should be included in a changelog entry for DELETE operations. Attributes specified in this list will be recorded in the deletedEntryAttrs attribute on the changelog entry when an entry is deleted. The attributes displayName and employeeNumber are indexed using the index-include-attribute property.
    $ bin/dsconfig set-backend-prop --backend-name changelog \
  --set "enabled:true" \
  --set "changelog-include-attribute:*" \
  --set "changelog-deleted-entry-include-attribute:*" \
  --set "index-include-attribute:displayName" \
  --set "index-include-attribute:employeeNumber"
  2. Add another attribute to index using the dsconfig --add option, which adds the attribute to an existing configuration setting. 
    $ bin/dsconfig set-backend-prop --backend-name changelog \
  --add "index-include-attribute:cn"