Enable query expansion

When you install Exalead CloudView, most query expansion modules are already activated, with the exception of Synonyms, or the Custom query expansion module.

By default, these modules are set up for all supported languages. You can, however, choose to add multiple instances of a query expansion module (for example, several lemmatization modules) that are set up for different languages.

However, if you want a certain prefix handler to use a query expansion module, you still need to configure that prefix handler’s query expansion accordingly.

To enable query expansion you need to do the following:

  • Activate query expansion modules: these are global processing units that must be defined for each search logic. They define the static parameters for the type of expansion. For example with synonym expansion, you must create a synonym dictionary, known as a resource file, for the synonym module.

  • In the prefix handler, define which modules to use for query expansion: this is defined in the Query expansion config for the prefix handler.­­

This task shows you how to:

See Also
Configuring Query Expansion
Query Tree and Query Expansion
Query Expansion Features

Activate a query expansion module

  1. In the Administration Console, go to Search > Search Logics > Query Expansion.
  2. Under Query expansion modules, click Add module if the module you want to activate does not already appear on the list.
  3. (Optional, except for Synonyms) Specify a resource file for the module. To define and compile a synonym resource file, see Synonyms.
  4. Click Save.

You must now associate this module with one or more prefix handlers as described in the following procedure.

Set up a prefix handler to use a query expansion module

  1. Go to the Query language tab and click the prefix handler that will use this module.
  2. In the expanded view of this prefix handler, click Edit beside Query expansion config.



  3. In the Query expansion config dialog, specify the semantic expansion for this prefix handler.

    You can also dynamic parameters for the expansion. In the following example, the expansion expression uses the approximate query expansion module, and includes specific options that define the maximum number of matches and their relative importance.



    For descriptions of the options available for each query expansion module, see:

  4. Click Apply.