Activate Synonyms in an IDOL Server

This solution is the easiest of the three synonym choices to implement, but is useful only if you require synonym matching for a maximum of approximately 100 terms. Beyond this limit, query response times experience a growing increase with the number of synonym terms, and it can have a negative impact on indexing performance.

Internal synonyms introduce the concept of expansion level; that is, the conceptual distance between synonyms. A synonym that you specify explicitly has an expansion level of zero. You can then expand the synonyms again, to get further expansions. For example, if there is a hierarchy of synonyms such that terrier expands to dog, and dog expands to animal, then:


To use synonyms in an IDOL Server, you must configure the [Synonym] section in the IDOL or Content server configuration file. In this section, you configure a list of synonym jobs, which are run at query time.

Each synonym job defines a file, which has a list of synonyms to process, and the MaxExpandLevel. For example:



The referenced file must contain comma-separated lists of synonymous terms and phrases for a particular language type. For example, myfile.txt might contain synonyms for animals:


You must also apply the SynonymType field property to any fields that you want to perform synonym expansion on. For example:


// Specify the fields that synonym expansion will be performed on

// Specify the synonym job to apply to those fields


After synonyms have been activated, you can use them by setting the Synonym action parameter to True in the Query action.