The CONTAINS operator is well suited to structured searching, enabling you to perform restrictive searches with the WITHIN, HASPATH, and INPATH operators. If you use a CONTEXT index, then you can also benefit from the following characteristics of Oracle Text searches:
Searches are token-based, whitespace-normalized
Hitlists are ranked by relevance
Case-sensitive searching
Section searching
Linguistic features such as stemming and fuzzy searching
Performance-optimized queries for large document sets
When Oracle Text is manually uninstalled, the DBMS_XDBT package should be dropped. When Oracle Text is manually reinstalled, the DBMS_XDBT package should be created.
Starting with Oracle Database 12c, Oracle XML Database is automatically installed when you install the new Oracle Database software or when you upgrade.