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:

Configuration

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:

[Synonym]
0=PC_Syn

[PC_Syn]
File=myfile.txt
MaxExpandLevel=1

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:

[EnglishUTF8]
dog,canine,puppy,hound,wolf
cat,feline,kitten,kitty

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

[FieldProcessing]
...
19=SynonymMatch

// Specify the fields that synonym expansion will be performed on
[SynonymMatch]
Property=ApplySynonymMatch
PropertyFieldCSVs=*/DRETITLE,*/DRECONTENT

// Specify the synonym job to apply to those fields
[ApplySynonymMatch]
SynonymType=PC_Syn

Usage

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


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