Add a Synonym Content Engine

Setting up a dedicated Content server to handle synonyms is a much more scalable solution than simply activating synonym support in an IDOL Server. A further benefit is that it is easier to update the synonyms, making this solution more dynamic. The dedicated synonym Content server holds documents that are simply lists of synonymous terms. A simple query to this server then returns the lists of synonyms.


Firstly, you must set up a Content component by following the normal process. Then you must index the synonym documents.

When you configure the field processing section of the Content configuration file, consider the following synonym document IDX:

#DRECONTENT cat feline grimalkin moggy mouser tabby kitten

You must use this format for all your synonym documents, where:

#DREREFERENCE is a unique reference string for the synonym document.
#DRECONTENT is a list of synonymous terms, separated by carriage returns or spaces (you cannot use phrases as synonyms).
#DREENDDOC is the normal delimiter for the end of a document in IDOL Server.

The usual method of producing synonym IDX files is to use a HTTP Connector to process a thesaurus Web site. With this method, you can also automatically index the documents. However, you can generate the files in any way, as long as the IDX is valid.


When you want to expand a query with synonyms, your user interface must send a query to the synonym server, for every term that it requires synonyms for. The server responds with the synonyms that can be added to the original query term. After all the synonyms have been processed, and the query text adjusted, the user interface sends the expanded query to the normal data server.


When you expand the query, you can improve your synonym matching by using the SYNONYM query operator. This operator specifies a list of synonymous terms to search for. In the query, IDOL Server returns results that contain any of the synonyms, but treats all the synonyms as a single term for result scoring. For example:

SYNONYM(cat feline grimalkin moggy mouser tabby kitten)

For more information, refer to the IDOL Server Administration Guide.