|Oracle8i interMedia Text Reference
Release 2 (8.1.6)
Part Number A77063-01
Query Operators, 3 of 26
In all languages, an ABOUT query increases the number of relevant documents returned from the same query without this operator. Oracle scores results to an ABOUT query with the most relevant document receiving the highest score.
In English, use the ABOUT operator to query on concepts. The system looks up concept information in the theme component of the index.
You need not have a theme component in the index to issue ABOUT queries in English. However, having a theme component in the index yields the best results for ABOUT queries.
Oracle retrieves documents that contain concepts that match your query word or phrase.
The word or phrase specified in your ABOUT query does not have to exactly match the themes stored in the index. Oracle automatically normalizes the word or phrase before performing lookup in the index.
In all languages, increases the number of relevant documents returned for the same query without the ABOUT operator.The phrase parameter can be a single word or a phrase, or a string of words in free text format.
The score returned is a relevance score.
To search for documents that are about soccer, use the following syntax:
You can further refine the query to include documents about soccer rules in international competition by entering the phrase as the query term:
In this English example, Oracle returns all documents that have themes of soccer, rules, or international competition.
In terms of scoring, documents which have all three themes will generally score higher than documents that have only one or two of the themes.
You can also query on unstructured phrases, such as the following:
You can use other operators, such as AND or NOT, to combine ABOUT queries with word queries.
For example, you can issue the following combined ABOUT and word query:
You can combine an ABOUT query with another ABOUT query as follows:
ABOUT queries give the best results when your query is formulated with proper case. This is because the normalization of your query is based on the knowledge catalog which is case-sensitive.
However, you need not type your query in exact case to obtain results from an ABOUT query. The system does its best to interpret your query. For example, if you enter a query of CISCO and the system does not find this in the knowledge catalog, the system might use Cisco as a related concept for look-up.
If an index contains only theme information, an ABOUT operator and operand must be included in a query on the text column or else Oracle returns an error.
Oracle ignores any query operators that are included in phrase.