query_rewrite_integrity

Description

The query_rewrite_integrity variable specifies the data consistency check level for materialized view-based query rewriting.

Privilege requirements

• Query variables

  • Global level

    The sys tenant and all user tenants can execute the SHOW VARIABLES statement or view SYS.TENANT_VIRTUAL_GLOBAL_VARIABLE (in Oracle mode) or information_schema.GLOBAL_VARIABLES (in MySQL mode) to view the value of a global system variable.

  • Session level

    The sys tenant and all user tenants can execute the SHOW VARIABLES statement or view SYS.TENANT_VIRTUAL_SESSION_VARIABLE (in Oracle mode) or information_schema.SESSION_VARIABLES (in MySQL mode) to view the value of a session system variable.

• Modify variables

  • Set the variable at the global level

    • The sys tenant can directly modify the value of a global system variable.

    • MySQL user tenants must have the SUPER or ALTER SYSTEM privilege to modify the value of a global system variable.

    • For V4.x, Oracle user tenants must have the ALTER SYSTEM privilege to modify the value of a global system variable starting from V4.2.0.

  • Set the variable at the session level

    The sys tenant and all user tenants can directly modify the value of a session system variable in their own tenant.

Attributes

Considerations

This variable is meaningful only when the value of the query_rewrite_enabled variable is not false.

Examples

The following examples show how to set the value of this variable to enforced for session-level and global-level effects, respectively.

• Set the variable at the session level

  obclient> SET  query_rewrite_integrity= enforced;
  

• Set the variable at the global level

  obclient> SET GLOBAL  query_rewrite_integrity= enforced;
  

References

Overview of materialized views