Specify a log restore endpoint

Standby tenants should be in continuous synchronization mode be default. This topic describes the procedure for setting a standby tenant to continuous synchronization mode.

Procedure

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

2. Execute the RECOVER statement to specify a 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.

   Execute the following statement in the sys tenant to specify the log restore endpoint for the standby tenant:

   ALTER SYSTEM RECOVER STANDBY TENANT = standby_tenant UNTIL UNLIMITED;
   

   Execute the following statement in the standby tenant to specify the log restore endpoint for the standby tenant:

   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