ZCTextIndex Add: Create a new ZCTextIndex

Description

A ZCTextIndex is an index for performing full text searches over bodies of text. It includes the following features:

• Boolean query operators with parenthetical grouping
• Globbing (partial word) and phrase matching
• Two selectable relevance scoring algorithms

ZCTextIndex is designed as a replacement for standard TextIndex, and has several advantages over it.

Controls

Id

The id of the ZCTextIndex, must be unique for this ZCatalog.

Field Name

The name of the field (object attribute) to be indexed.

Ranking Strategy

• Okapi BM25 Rank A relevance scoring technique that seems to work well when the document text is considerably longer than the query string, which is often the case with user specified query strings.
• Cosine Measure A relevance scoring technique derived from the Managing Gigabytes book. It seems to work best when the queries are similar in size and content to the text they are searching.

Lexicon

The ZCTextIndex Lexicon to be used by this ZCTextIndex. Lexicons process and store the words from the text and help in processing queries. You must define a ZCTextIndex Lexicon before you can create a ZCTextIndex. Several ZCTextIndexes can share the same Lexicon if desired.