If your CONTAINS() query also has structured predicates on the non-text columns, then you may consider having the Text index also index those column values. To do so, specify those columns in the FILTER BY clause of the CREATE INDEX statement. This enables Oracle Text to determine whether to have the structured predicate(s) also be processed by the Text index for better performance.
Additionally, if your CONTAINS() query has ORDER BY criteria on one or more structured columns, then the Text index can also index those column values. Specify those columns in the ORDER BY clause of the CREATE INDEX statement. This enables Oracle Text to determine whether to push the sort into the Text index for better query response time.