System-Defined Preferences

When you install Oracle Text, some indexing preferences are created. You can use these preferences in the parameter clause of CREATE INDEX or define your own.

The default index parameters are mapped to some of the system-defined preferences described in this section.

See Also: For more information about default index parameters, see "Default Index Parameters" .

System-defined preferences are divided into the following categories:

• Data Storage

• Filter

• Lexer

• Section Group

• Stoplist

• Storage

• Wordlist

Data Storage

CTXSYS.DEFAULT_DATASTORE

This preference uses the DIRECT_DATASTORE type. You can use this preference to create indexes for text columns in which the text is stored directly in the column.

CTXSYS.FILE_DATASTORE

This preference uses the FILE_DATASTORE type.

CTXSYS.URL_DATASTORE

This preference uses the URL_DATASTORE type.

Filter

CTXSYS.NULL_FILTER

This preference uses the NULL_FILTER type.

CTXSYS.INSO_FILTER

This preference uses the INSO_FILTER type.

Lexer

CTXSYS.DEFAULT_LEXER

The default lexer depends on the language used at install time. The following sections describe the default settings for CTXSYS.DEFAULT_LEXER for each language.

American and English Language Settings

If your language is English, this preference uses the BASIC_LEXER with the index_themes attribute disabled.

Danish Language Settings

If your language is Danish, this preference uses the BASIC_LEXER with the following option enabled:

• alternate spelling (alternate_spelling attribute set to DANISH)

Dutch Language Settings

If your language is Dutch, this preference uses the BASIC_LEXER with the following options enabled:

• composite indexing (composite attribute set to DUTCH)

• alternate spelling (alternate_spelling attribute set to DUTCH)

German and German DIN Language Settings

If your language is German, this preference uses the BASIC_LEXER with the following options enabled:

• case-sensitive indexing (mixed_case attribute enabled)

• composite indexing (composite attribute set to GERMAN)

• alternate spelling (alternate_spelling attribute set to GERMAN)

Finnish, Norwegian, and Swedish Language Settings

If your language is Finnish, Norwegian, or Swedish, this preference uses the BASIC_LEXER with the following option enabled:

• alternate spelling (alternate_spelling attribute set to SWEDISH)

Japanese Language Settings

If you language is Japanese, this preference uses the JAPANESE_VGRAM_LEXER.

Korean Language Settings

If your language is Korean, this preference uses the KOREAN_MORPH_LEXER. All attributes for the KOREAN_MORPH_LEXER are enabled.

Simplified Chinese Language Settings

If your language is Simplified Chinese, this preference uses the CHINESE_VGRAM_LEXER.

Other Languages

For all other languages not listed in this section, this preference uses the BASIC_LEXER with no attributes set.

See Also: To learn more about these options, see BASIC_LEXER .

CTXSYS.BASIC_LEXER

This preference uses the BASIC_LEXER.

Section Group

CTXSYS.NULL_SECTION_GROUP

This preference uses the NULL_SECTION_GROUP type.

CTXSYS.HTML_SECTION_GROUP

This preference uses the HTML_SECTION_GROUP type.

CTXSYS.AUTO_SECTION_GROUP

This preference uses the AUTO_SECTION_GROUP type.

CTXSYS.PATH_SECTION_GROUP

This preference uses the PATH_SECTION_GROUP type.

Stoplist

CTXSYS.DEFAULT_STOPLIST

This stoplist preference defaults to the stoplist of your database language.

See Also: For a complete list of the stop words in the supplied stoplists, see Appendix D, "Supplied Stoplists".

CTXSYS.EMPTY_STOPLIST

This stoplist has no words.

Storage

CTXSYS.DEFAULT_STORAGE

This storage preference uses the BASIC_STORAGE type.

Wordlist

CTXSYS.DEFAULT_WORDLIST

This preference uses the language stemmer for your database language. If your language is not listed in Table 2-1, this preference defaults to the NULL stemmer and the GENERIC fuzzy matching attribute.