Backup metadata for restoration

The backup data in OceanBase Database comprises data backups and log backups.

• Each data backup corresponds to a backup_set directory. Each time the alter system backup database command is executed, a new backup_set directory that contains all data that is backed up this time is generated.

• For log backup, users can specify whether to split directories by day. If directory splitting is enabled, the log backup data of each day corresponds to a backup_piece directory. If directory splitting is not enabled, all the log backup data corresponds to one backup_piece directory.

In OceanBase Database, the backup metadata refers to the data of the backup_set and backup_piece directories, and the tenant information.

• backup_set data: stored in the tenant_data_backup_info file for a tenant on the backup media, and stored in the oceanbase.__all_backup_set_files table in the source cluster.

• backup_piece data: stored in the tenant_clog_backup_info file for a tenant on the backup media, and stored in the oceanbase.__all_backup_piece_files table in the source cluster.

• Tenant information: stored in the tenant_name_info file on the backup media, and stored in the oceanbase.__all_tenant and oceanbase.__all_tenant_history tables in the source cluster.