This topic describes the limitations on the Physical Standby Database feature.
| Item | Description |
|---|---|
| Number of standby tenants | Unlimited |
| Heterogeneity of the primary and standby tenants |
|
| Synchronization of parameter modifications between the primary and standby tenants | The parameters of the primary tenant are independent of those of a standby tenant, and parameter modifications are not physically synchronized. After you modify a parameter for the primary tenant, you must assess whether to modify this parameter for the standby tenants. |
| Synchronization of system variable modifications between the primary and standby tenants | After a system variable is modified in the primary tenant, the modification is synchronized to the standby tenants. |
| Operations in standby tenants |
|
| Switchover |
|
| Failover | Make sure that all servers in the cluster to which the standby tenant belongs are online. |