Specify a log restore endpoint

By default, standby tenants should be in continuous synchronization mode. If the standby tenant is not in continuous synchronization mode, refer to this topic to set it to continuous synchronization mode.

Procedure

1. Log in as the administrator to the standby tenant or the sys tenant of the cluster where the standby tenant resides.

2. Execute the RECOVER command to set the log restore endpoint for the standby tenant.

   ALTER SYSTEM RECOVER STANDBY [TENANT = tenant_name] UNTIL UNLIMITED;
   

   Note that the parameter TENANT = tenant_name is only required when you execute the statement with the sys tenant to specify the name of the standby tenant. UNLIMITED indicates that the endpoint is infinite.

   Example of the sys tenant setting the log restore endpoint for the standby tenant:

   ALTER SYSTEM RECOVER STANDBY TENANT = standby_tenant UNTIL UNLIMITED;
   

   Example of the standby tenant setting the log restore endpoint for itself:

   ALTER SYSTEM RECOVER STANDBY UNTIL UNLIMITED;
   

   After you execute this statement, the standby tenant enters the continuous synchronization mode.

More information

OceanBase Database also allows you to execute the RECOVER statement to set the restore endpoint for the standby tenant to any appropriate point in time. The syntax is as follows:

• Restore to a specified timestamp

  ALTER SYSTEM RECOVER STANDBY [TENANT = tenant_name] UNTIL TIME='timestamp';
  

• Restore to a specified SCN

  ALTER SYSTEM RECOVER STANDBY [TENANT = tenant_name] UNTIL SCN =scn;
  

where:

• TENANT = tenant_name is only required when you execute the statement with the sys tenant to specify the name of the standby tenant.

• timestamp is a specified timestamp in nanoseconds.

• scn is a specified SCN, which is a logical internal timestamp.

After the statement is executed, the standby tenant will recover to the specified time point, including that time point.

References

• Create a standby tenant by using the backup and restore (with complete logs) feature

• Create a standby tenant by using the BACKUP DATABASE PLUS ARCHIVELOG feature