BACKUP

The ALTER SYSTEM BACKUP statement is used to initiate a data backup. Data backups include full backups and incremental backups.

A full backup backs up all macroblocks, while an incremental backup backs up all new and modified macroblocks since the last full backup.

Limitations and considerations

• Before initiating a data backup, ensure that the archive mode is enabled and the status of the archive task is DOING.

  For more information about how to view the status of log archive tasks, see View the archive progress.

  For more information about how to enable the archive mode, see ARCHIVELOG.

• To perform an incremental data backup, ensure that a full data backup already exists. If you initiate an incremental backup without a full backup, the system will automatically convert the incremental backup into a full backup.

• In scenarios where a low-version cluster is upgraded to a high-version cluster, even if a full backup has been performed on the low-version tenant, initiating an incremental backup in the high-version cluster will automatically convert the incremental backup into a full backup.

Privilege requirements

The operation must be performed by the root user of the sys tenant (root@sys) or the administrator of each tenant. Specifically:

• In MySQL mode, the default administrator is the root user.
• In Oracle mode, the default administrator is the SYS user.

Syntax

ALTER SYSTEM backup_action [DESCRIPTION [=] 'desprition'];

backup_option:
      BACKUP DATABASE [PLUS ARCHIVELOG]
    | BACKUP TENANT [=] {tenant_name[, tenant_name]...} [PLUS ARCHIVELOG]
    | BACKUP INCREMENTAL DATABASE
    | BACKUP INCREMENTAL TENANT [=] {tenant_name[, tenant_name]...}

Parameters

Examples

Assume that the current cluster has three tenants: sys, mysql_tenant, and oracle_tenant, and both mysql_tenant and oracle_tenant have completed the necessary preparations before initiating a data backup.

• For the sys tenant:

  • Initiate a full data backup for all user tenants in the cluster.

    obclient [oceanbase]> ALTER SYSTEM BACKUP DATABASE;
    

    After executing this statement, the system will initiate a full data backup for the mysql_tenant and oracle_tenant tenants in the cluster.

  • Initiate a full data backup for the mysql_tenant tenant.

    obclient [oceanbase]> ALTER SYSTEM BACKUP TENANT = mysql_tenant;
    

  • Initiate a full data backup for the mysql_tenant tenant, including archive logs.

    obclient [oceanbase]> ALTER SYSTEM BACKUP TENANT = mysql_tenant PLUS ARCHIVELOG;
    

    After executing this statement, the system will generate a complete dataset containing archive logs in the data backup directory of the mysql_tenant tenant. For community edition and standalone edition users, in a physical standby database scenario, you can use this dataset to create a standby tenant. For detailed operations on how to create a standby tenant using a dataset with archive logs, see Create a standby tenant using the BACKUP DATABASE PLUS ARCHIVELOG feature.

  • Initiate an incremental data backup for all tenants in the cluster.

    obclient [oceanbase]> ALTER SYSTEM BACKUP INCREMENTAL DATABASE;
    

    After executing this statement, the system will initiate an incremental data backup for the mysql_tenant and oracle_tenant tenants in the cluster.

  • Initiate an incremental data backup for the mysql_tenant tenant.

    obclient [oceanbase]> ALTER SYSTEM BACKUP INCREMENTAL TENANT = mysql_tenant;
    

• For user tenants:

  • Initiate a full data backup for the mysql_tenant tenant.

    obclient [oceanbase]> ALTER SYSTEM BACKUP DATABASE;
    

  • Initiate a full data backup for the oracle_tenant tenant, including archive logs.

    obclient [SYS]> ALTER SYSTEM BACKUP DATABASE PLUS ARCHIVELOG;
    

  • Initiate an incremental data backup for the mysql_tenant tenant.

    obclient [oceanbase]> ALTER SYSTEM BACKUP INCREMENTAL DATABASE;
    

References

• ARCHIVELOG

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