Full text search can quickly find all instances of a term (word) in a database without having to scan table rows and without having to know which column a term is stored in. Full text search works by using text indexes. A text index stores positional information for terms in the indexed column(s). Using a text index to find rows that contain a term can be faster than scanning every row in the table for the same reasons that it can be faster to use a regular index to find rows containing a given value. See Text indexes.
Full text search uses the CONTAINS search condition. It differs from searching using predicates such as LIKE, REGEXP, and SIMILAR TO, because the matching is term-based and not pattern-based. See CONTAINS search condition.
String comparisons in full text search use all the normal collation settings for the database. For example, if the database is configured to be case insensitive, then full text searches will be case insensitive. See Understanding collations.
Except where noted, full text search leverages all the international features supported by SQL Anywhere. See SQL Anywhere international features.
To perform a full text search on a database containing Chinese, Japanese, and Korean (CJK) data, see the whitepaper Performing Full Text Searches on Chinese, Japanese, and Korean Data in SQL Anywhere 11 which is available at http://www.sybase.com/detail?id=1061814.
|Envoyer votre avis sur cette page par email.||Copyright © 2009, iAnywhere Solutions, Inc. - SQL Anywhere 11.0.1|