| Property | Description | 
|---|---|
| Parameter type | String | 
| Syntax | QUERY_REWRITE_INTEGRITY = { enforced | trusted | stale_tolerated } | 
| Default value | enforced | 
| Modifiable | ALTER SESSION,ALTER SYSTEM | 
| Real Application Clusters | Multiple instances can have different values. | 
QUERY_REWRITE_INTEGRITY determines the degree to which Oracle must enforce query rewriting. At the safest level, Oracle does not use query rewrite transformations that rely on unenforced relationships.
Values:
enforced
Oracle enforces and guarantees consistency and integrity.
trusted
Oracle allows rewrites using relationships that have been declared, but that are not enforced by Oracle.
stale_tolerated
Oracle allows rewrites using unenforced relationships. Materialized views are eligible for rewrite even if they are known to be inconsistent with the underlying detail data.