Alters a text configuration object.
ALTER TEXT CONFIGURATION [ owner.]config-name STOPLIST stoplist | DROP STOPLIST | { MINIMUM | MAXIMUM } TERM LENGTH integer | TERM BREAKER { GENERIC [ EXTERNAL NAME library-and-entry-point-name-string ] | NGRAM } | PREFILTER EXTERNAL NAME library-and-entry-point-name-string
CREATE TEXT CONFIGURATION maxTerm16 FROM default_char;
ALTER TEXT CONFIGURATION maxTerm16 MAXIMUM TERM LENGTH 16;
ALTER TEXT CONFIGURATION maxTerm16
STOPLIST 'because about therefore only';
CREATE TEXT CONFIGURATION my_text_config FROM default_char;
ALTER TEXT CONFIGURATION my_text_config
TERM BREAKER GENERIC EXTERNAL NAME 'platform:my_term_breaker@mytermbreaker';
ALTER TEXT CONFIGURATION my_text_config PREFILTER EXTERNAL NAME 'platform:my_prefilter@myprefilter';
Use ALTER TEXT CONFIGURATION to change a text configuration object.
TEXT indexes are dependent on a text configuration object. SAP Sybase IQ TEXT indexes use immediate refresh, and cannot be truncated; you must drop the indexes before you can alter the text configuration object.
To view the settings for text configuration objects, query the SYSTEXTCONFIG system view.
STOPLIST clause – use this clause to create or replace the list of terms to ignore when building a TEXT index. Terms specified in this list are also ignored in a query. Separate stoplist terms with spaces.
Stoplist terms cannot contain whitespace. Stoplist terms should not contain non-alphanumeric characters. Non-alphanumeric characters are interpreted as spaces and break the term into multiple terms. For example, “and/or” is interpreted as the two terms “and” and “or”. The maximum number of stoplist terms is 7999.
Terms that are shorter than this setting are ignored when building or refreshing the TEXT index. The value of this option must be greater than 0. If you set this option to be higher than MAXIMUM TERM LENGTH, the value of MAXIMUM TERM LENGTH is automatically adjusted to be the same as the new MINIMUM TERM LENGTH value.
The value of MAXIMUM TERM LENGTH must be less than or equal to 60. If you set this option to be lower than MINIMUM TERM LENGTH, the value of MINIMUM TERM LENGTH is automatically adjusted to be the same as the new MAXIMUM TERM LENGTH value.
The NGRAM algorithm breaks strings into n-grams. An n-gram is an n-character substring of a larger string. The NGRAM term breaker is required for fuzzy (approximate) matching, or for documents that do not use whitespace or non-alphanumeric characters to separate terms. NGRAM is supported for IN SYSTEM tables.
NGRAM term breaker is built on TEXT indexes, so use text configuration object settings to define whether to use an NGRAM or GENERIC TEXT index.
TERM BREAKER can include the specification for the external term breaker library using EXTERNAL NAME and the library entry point.
All other clauses – Requires the ALTER ANY TEXT CONFIGURATION system privilege, regardless of whether the user is the owner of the configuration object.