Stoplists and Stopwords

Pre-8.1

In pre-8.1 a stoplist consisted of words that are not to be indexed. You recorded these words by calling CTX_DDL.SET_ATTRIBUTE for each stopword and then by creating a stoplist preference with CTX_DDL.CREATE_PREFERENCE.

Default stoplists in most of the supported languages are available. You manually set the stoplist fro your language.

8.1

Stoplists

A stoplist consists of words that are not to be indexed. The definition has not changed in 8.1.

Default Stoplist

By default, they system sets the default stoplist to the language you specify in your database setup. There is no need to create or set stoplists, unless you want to customize the list.

Stopthemes and Stopclasses

In addition to defining your own stopwords in 8.1, you can define stopthemes, which are themes that are not to be indexed. This is available for English only.

You can also specify that numbers are not to be indexed. A class of alphanumeric characters such a numbers that is not to be indexed is a stopclass.

You record your own stopwords, stopthemes, stopclasses by creating a single stoplist, to which you add the stopwords, stopthemes, and stopclasses. You specify the stoplist in the paramstring for CREATE INDEX.

New Procedures

In 8.1, you use the following procedures to manage stopwords, stopthemes, and stopclasses:

• CTX_DDL.CREATE_STOPLIST

• CTX_DDL.ADD_STOPWORD

• CTX_DDL.ADD_STOPTHEME

• CTX_DDL.ADD_STOPCLASS

• CTX_DDL.REMOVE_STOPWORD

• CTX_DDL.REMOVE_STOPTHEME

• CTX_DDL.REMOVE_STOPCLASS

• CTX_DDL.DROP_STOPLIST

  See Also: To learn more about using these commands, see the Oracle8i interMedia Text Reference.