Restoration architecture

The following figure shows the physical restoration architecture of OceanBase Database.

Two steps in the restoration procedure are visible to users:

1. Use the CREATE RESOURCE POOL command to create the resource pool required by the tenant restoration in the target cluster.

2. Use the ALTER SYSTEM RESTORE TENANT command to schedule tenant restoration tasks.

The following procedure is the internal procedure of the RESTORE TENANT command for backup restoration:

1. Create the tenant for restoration

2. Restore the system table data of the tenant

3. Restore system table logs of the tenant

4. Restore the metadata of the tenant

5. Restore the user table data of the tenant

6. Restore user table logs of the tenant

7. Outstanding works of restoration

For a single partition group (PG), the metadata and macroblock data of the PG are replicated to the specified OBServer to build a PG with only baseline data. Then, the logs in the PG are replicated to the specified OBServer and put back to the MemTable in the PG. In this procedure, if the number of logs is large, you may need to dump these logs.