[Zope-Annce] [ANN] TextIndexNG 2.0 alpha 1 released

Andreas Jung Andreas Jung <andreas@andreas-jung.com>
Sun, 04 May 2003 10:54:42 +0200

I am pleased to announce the release of TextIndexNG 2.0 alpha1 .

What's new in TextIndexNG 2.0?

  - Relevance ranking of search results added. Searches are now ranked
    using an extended cosine measure. The cosine measure is based on
    a vector model and calculates the document "score" based on the
    frequency of the query terms inside the document result set.

  - Much faster phrase/near search: the old implementation of TextIndexNG
    had to perform a very expensive job at query time when phrase/near 
    was performed. Re-using the !WidCode module of !ZCTextIndex made
    this operation less expensive.

  - Left-truncation added: TextIndexNG can be configured creation-time
    time to support left-truncation (means you can search for "*suffix")

  - optional auto-expansion support: This optional feature also to get
    better search results when some of the query terms could not be found.
    The index expands a query term "foo" to "foo*" if there was no hit
    for "foo". This expansion is currently global for the index. This 
    will be available on a per-query basis in a later version. 
    will be extended in a later version to search for similiar terms)

  - improved HTML converter: now using  Chris Withers "Strip-o-Gram" module
    instead of the Strip-Tag-Parser

  - added converter for text/sgml

  - Similarity search (soundex, metaphone, doublemetaphone) dropped
    and replace with a more general approach and language indepedant
    approach using the Levenshtein distance.

  - internal code cleanup, more unittests

 Not implemented yet

  - improved support for multilingual documents

  - range searches like "Fi..Foo"

  - substring searches "*substring*"

  - optional improved ranking for terms based on their relative positions
    inside a document

Installation notes

  TextIndexNG 2.0 is *not compatible* with TextIndexNG 1.0 so there
  is currently no migration path for existing indexes.

  - **BACKUP YOUR Data.fs first!!!**

  - remove any existing TextIndexNG from your ZCatalog indexes

  - shutdown Zope

  - remove the old Products/TextIndexNG directory

  - untar the tarball in the Products folder

  - recompile and install extension modules (see InstallationInstructions)

  - restart Zope

  - re-create the indexes and re-index



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