ADD_SPECIAL_SECTION

Adds a special section, either SENTENCE or PARAGRAPH, to a section group. This enables searching within sentences or paragraphs in documents with the WITHIN operator.

A special section in a document is a section which is not explicitly tagged like zone and field sections. The start and end of special sections are detected when the index is created. Oracle supports two such sections: paragraph and sentence.

The sentence and paragraph boundaries are determined by the lexer. Therefore, if the lexer cannot recognize the boundaries, no sentence or paragraph sections are indexed.

Syntax

CTX_DDL.ADD_SPECIAL_SECTION(
                 group_name    IN VARCHAR2, 
                 section_name  IN VARCHAR2);

group_name

Specify the name of the section group.

section_name

Specify SENTENCE or PARAGRAPH.

Example

The following code enables searching within sentences within HTML documents:

begin
ctx_ddl.create_section_group('htmgroup', 'HTML_SECTION_GROUP');
ctx_ddl.add_special_section('htmgroup', 'SENTENCE');
end;

You can also add zone sections to the group to enable zone searching in addition to sentence searching. The following example adds the zone section Headline to the section group htmgroup:

begin
ctx_ddl.create_section_group('htmgroup', 'HTML_SECTION_GROUP');
ctx_ddl.add_special_section('htmgroup', 'SENTENCE');
ctx_ddl.add_zone_section('htmgroup', 'Headline', 'H1');
end;

If you are only interested in sentence or paragraph searching within documents and not interested in defining zone or field sections, you can use the NULL_SECTION_GROUP as follows:

begin
ctx_ddl.create_section_group('nullgroup', 'NULL_SECTION_GROUP');
ctx_ddl.add_special_section('nullgroup', 'SENTENCE');
end;

Related Topics

WITHIN operator in Chapter 3, "CONTAINS Query Operators".

"Section Group Types" in Chapter 2, "Indexing".

CREATE_SECTION_GROUP

ADD_ZONE_SECTION

ADD_FIELD_SECTION

REMOVE_SECTION

DROP_SECTION_GROUP