A thesaurus is a list of terms or phrases with relationships specified among them, such as a synonym, a broader term, and a narrower term. When a user issues a search query, Oracle SES can expand the search results to include matches for the related terms.
A thesaurus contains domain-specific knowledge. You can build a thesaurus, buy an industrial-specific thesaurus, or use utilities to extract a thesaurus from a specific corpus of documents. The thesaurus must be compliant with both the ISO-2788 and ANSI Z39.19(1993) standards.
A thesaurus must be loaded in Oracle SES for thesaurus-based query expansion. If no thesaurus is loaded or if the specified term or phrase cannot be found in the loaded thesaurus, then query expansion is not possible. Oracle SES only returns documents containing the original term or phrase. The default expansion level is one.
The proper encoding of an XML document for thesaurus configuration is UTF-8, which is the Oracle SES default language setting. Ensure that the NLS_LANG environment variable setting is consistent with the XML document encoding.
--NAME=object_name -n object_name
create delete export getAllObjectKeys update
<search:thesauruses> element defines a thesaurus:
<search:thesaurus> element, which describes a thesaurus.
Describes a thesaurus. It contains these child elements:
The name of the thesaurus. This name must be
The thesaurus content. (Required)
dog BT mammal NT domestic dog NT wild dog SYN canine
This XML document defines the default thesaurus:
<?xml version="1.0" encoding="UTF-8"?> <search:config productVersion="220.127.116.11.0" xmlns:search="http://xmlns.oracle.com/search"> <search:thesauruses> <search:thesaurus> <search:name>DEFAULT</search:name> <search:thesaurusContent> <![CDATA[ cat SYN feline NT domestic cat NT wild cat BT mammal mammal BT animal domestic cat NT Persian cat NT Siamese cat wild cat NT tiger tiger NT Bengal tiger dog BT mammal NT domestic dog NT wild dog SYN canine domestic dog NT German Shepard wild dog NT Dingo ]]> </search:thesaurusContent> </search:thesaurus> </search:thesauruses> </search:config>