Document Sections

Defining document sections before you index enables you to query within the sections using the WITHIN operator. You define sections as part of a section group.

Pre-8.1

In pre-8.1, you create a section group and specify it in the Wordlist preference. You can create only user-defined zone sections and sentence and paragraph sections.

8.1

Section Groups

In 8.1, you create a section group and specify it in the paramstring for CREATE INDEX. To create a section group, use CTX_DDL.CREATE_SECTION_GROUP.

See Also: to learn more about using CTX_DDL.CREATE_SECTION_GROUP, see its specification in the Oracle8i interMedia Text Reference.

You can create different types of section groups. You can create a basic section group that allows you to define your own sections or you can create section groups that automatically create sections from HTML or XML documents during indexing.

Within a basic section group, you can create three types of sections:

• Zone Sections (formerly user-defined section)

• Field Sections (new)

• Special Sections (sentence and paragraph sections)

Zone Sections

Zone sections (formerly known as user-defined sections in pre-8.1) are sections delimited by start and end tags. The <B> and </B> tags in HTML for instance, marks a range of words which are to be rendered in boldface.

Zone sections can be nested within one another, can overlap, and can occur more than once in a document.

You create zone sections as part of a section group with CTX_DDL.ADD_ZONE_SECTION.

See Also: to learn more about using CTX_DDL.ADD_ZONE_SECTION, see its specification in the Oracle8i interMedia Text Reference.

Field Sections

Field sections are new for 8.1. Field sections are delimited by start and end tags. By default, the text within field sections are indexed as a sub-document separate from the rest of the document.

Unlike zone sections, field sections cannot nest or overlap. As such, field sections are best suited for non-repeating, non-overlapping sections such as TITLE and AUTHOR sections in news type documents.

Because of how field sections are indexed, WITHIN queries on field sections are usually faster than WITHIN queries on zone sections.

You create a field section as part of a section group using CTX_DDL.ADD_FIELD_SECTION procedure.

See Also: to learn more about using CTX_DDL.ADD_FIELD_SECTION, see its specification in the Oracle8i interMedia Text Reference.

Special Sections

In 8.1, special sections are the same as paragraph and sentence sections in pre-8.1.

To create sentence and paragraph sections, use the CTX_DDL.ADD_SPECIAL_SECTION procedure.

See Also: to learn more about using CTX_DDL.ADD_SPECIAL_SECTION, see its specification in the Oracle8i interMedia Text Reference.

8.1.6 Improvements to Document Sections

The following sections describe the enhancements to release 8.1.6. You might consider using the automatic sectioner and attribute section features if your pre-8.1 document set is primarily XML documents.

Automatic Sectioner

In 8.1.6, interMedia Text has a new automatic sectioner AUTO_SECTION_GROUP that automatically sections XML documents, creating zone sections for each start-tag/end-tag pair.

Attribute Sections

You can define attribute text as sections when you use the XML_SECTION_GROUP for sectioning XML documents. Defining attribute sections allows you to search XML attribute text with the WITHIN operator.

Attribute sections are also automatically defined when you use the AUTO_SECTION_GROUP.

Document Type Sensitive Sections

You can create doctype sensitive sections when you use the XML_SECTION_GROUP. When you create such sections across an XML document set, you can limit your WITHIN section searches to a specific document type.

Indexing META Tags

When you use the HTML_SECTION_GROUP, you can define the META tag's NAME and CONTENT attributes as zone or field sections. This allows you to search NAME and CONTENT attribute with the WITHIN operator.

Dynamic Addition of Sections

You can add sections (zone, field, and attribute) after indexing using the SQL command ALTER INDEX. Note, however, that the new sections are not queryable until you re-index your document set.

See Also: For information about the features discussed in this section, see Oracle8i interMedia Text Reference