POLICY_GIST

Generates a gist or theme summary for document. You can generate paragraph-level or sentence-level gists or theme summaries. With this procedure, no CONTEXT index is required.

Syntax

ctx_doc.policy_gist(policy_name      in VARCHAR2,
                    document         in [VARCHAR2|CLOB|BLOB|BFILE],
                    restab           in out nocopy CLOB,
                    glevel           in VARCHAR2 default 'P',
                    pov              in VARCHAR2 default 'GENERIC',
                    numParagraphs    in NUMBER default NULL,
                    maxPercent       in NUMBER default NULL,
                    num_themes       in NUMBER default 50
                    language         in VARCHAR2 default NULL,
                    format           in VARCHAR2 default NULL,
                    charset          in VARCHAR2 default NULL
);

policy_name

Specify the policy name created with CTX_DDL.CREATE_POLICY.

document

Specify the document for which to generate the Gist or theme summary.

restab

Specify the name of the CLOB locator.

glevel

Specify the type of gist or theme summary to produce. The possible values are:

The default is P.

pov

Specify whether a gist or a single theme summary is generated. The type of gist or theme summary generated (sentence-level or paragraph-level) depends on the value specified for glevel.

To generate a gist for the entire document, specify a value of ‘GENERIC’ for pov. To generate a theme summary for a single theme in a document, specify the theme as the value for pov.

When using result table storage and you do not specify a value for pov, this procedure returns the generic gist plus up to 50 theme summaries for the document.

Note:

The pov parameter is case sensitive. To return a gist for a document, specify ‘GENERIC’ in all uppercase. To return a theme summary, specify the theme exactly as it is generated for the document.

Only the themes generated by THEMES for a document can be used as input for pov.

numParagraphs

Specify the maximum number of document paragraphs (or sentences) selected for the document gist or theme summaries. The default is 16.

Note:

The numParagraphs parameter is used only when this parameter yields a smaller gist or theme summary size than the gist or theme summary size yielded by the maxPercent parameter.

This means that the system always returns the smallest size gist or theme summary.

maxPercent

Specify the maximum number of document paragraphs (or sentences) selected for the document gist or theme summaries as a percentage of the total paragraphs (or sentences) in the document. The default is 10.

Note:

The maxPercent parameter is used only when this parameter yields a smaller gist or theme summary size than the gist or theme summary size yielded by the numParagraphs parameter.

This means that the system always returns the smallest size gist or theme summary.

num_themes

Specify the number of theme summaries to produce when you do not specify a value for pov. For example, if you specify 10, this procedure returns the top 10 theme summaries. The default is 50.

If you specify 0 or NULL, this procedure returns all themes in a document. If the document contains more than 50 themes, only the top 50 themes show conceptual hierarchy.

language

Specify the language of the document. Use an Oracle Text supported language value as you would in the language column of the base table. See “MULTI_LEXER”.

format

Specify the format of the document. Use an Oracle Text supported format value, either TEXT, BINARY or IGNORE as you would specify in the format column of the base table. For more information, see the format column description in “CREATE INDEX”.

charset

Specify the character set of the document. Use an Oracle Text supported value as you would specify in the charset column of the base table.