Greek Stemmer

The problem

Drupal's core search module requires an absolute match between the query word and a word e.g. in a node in order to return the node as a result to the user. In the Greek language words tend to have many forms that depend on many factors (e.g. grammatical), a fact that almost completely ruins the core search of Drupal.

The proposed solution

Stemming is performed to all words in the search query and to all words in all searchable content types (e.g. nodes etc..)

Initial Drupal implementation

by Vassilis Spiliopoulos (http://users.iit.demokritos.gr/~vspiliop/)

Port to Drupal 6, 7, 8

by yannisc (https://www.netstudio.gr)

Port to Drupal 9, 10

by E-sepia Web Innovation (https://www.e-sepia.gr)

History

From Wikipedia (http://en.wikipedia.org/wiki/Stemming):
Stemming is the process for reducing inflected (or sometimes derived) words to their stem,
base or root form - generally a written word form. The stem need not be identical to the morphological root of the word; it is usually sufficient that related words map to the same stem, even if this stem is not in itself a valid root.

As a result, the search returns more results (in contrast to none in many cases, if no stemming is used).

The algorithm used is described in the master thesis of Georgios Ntais at Royal Institute of Technology [KTH], Stockholm Sweden (http://www.dsv.su.se/~hercules/papers/Ntais_greek_stemmer_thesis_final.pdf)

Installation

1. Install and Enable the module as you normally do with all modules.
2. Go to "administer" -> "settings" -> "search" and click "Re-index site".
3. Run cron.php (http://example.com/cron.php)

Uninstall

1. Disable and uninstall the module as you normally do with all modules.
2. Delete the module folder from the modules directory
3. Go to "administer" -> "settings" -> "search" and click "Re-index site".
4. Run cron.php (http://example.com/cron.php).