BACKUP

You can use the ALTER SYSTEM BACKUP statement to initiate a data backup. OceanBase Database supports full backup and incremental backup.

A full backup backs up all macroblocks. An incremental backup backs up all macroblocks generated and modified since the last full backup.

In addition to using the default path specified by the system parameter data_backup_dest, you can also use the TO '<dest>' syntax to back up data to a specified path. This is a one-time operation that does not modify the system parameter or affect subsequent automatic scheduled backups. For more information, see Back up to a specified directory.

Limitations and considerations

• Before you initiate a data backup, make sure that the archive mode is enabled and the STATUS of the log archive job is DOING.

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

  For more information about the syntax for enabling the archive mode, see ARCHIVELOG.

• Make sure that a full backup has been performed. If you initiate an incremental backup when no full backup is available, the system automatically downgrades the incremental backup to a full backup.

• In the scenario where a cluster is upgraded from a lower version to a later version (the current version), even if the current tenant has already performed a full backup in the lower version, if you directly initiate an incremental backup after the upgrade, the system automatically downgrades the incremental backup to a full backup.

• When you use the TO '<dest>' syntax to specify a backup target path, note the following limitations:

  • The system tenant can only specify one tenant by using the TO syntax. You cannot initiate backups for multiple tenants at the same time. This is because multiple tenants would share the same target root path, which would cause backup sets of different tenants to overwrite each other.
  • If no historical backups exist in the specified target path (first-time backup), the incremental backup is automatically downgraded to a full backup.

Required privileges

Only the root user of the sys tenant (root@sys) or the administrator user of a user tenant can execute this statement.

• The default administrator user in MySQL-compatible mode is root.
• The default administrator user in Oracle-compatible mode is SYS.

Syntax

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

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

Parameters

Examples

Assume that the current cluster contains three tenants: sys, mysql_tenant, and oracle_tenant, and that backup preparations have been completed for the mysql_tenant and oracle_tenant tenants.

• sys tenant

  • In the sys tenant, initiate a full data backup for all user tenants in the cluster.

    obclient [oceanbase]> ALTER SYSTEM BACKUP DATABASE;
    

    After the statement is executed, the system initiates a full data backup for the mysql_tenant and oracle_tenant tenants in the cluster.

  • In the sys tenant, initiate a full data backup for the mysql_tenant tenant.

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

  • In the sys tenant, initiate a full data backup that also backs up archive logs for the mysql_tenant tenant.

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

    After the statement is executed, the system generates a complete data set with archive logs in the data backup path of the tenant. If you use OceanBase Database Community Edition or OceanBase Database in standalone mode, you can use this data set to create a standby tenant in the physical standby database scenario. For more information, see Create a standby tenant by using the BACKUP DATABASE PLUS ARCHIVELOG feature.

  • In the sys tenant, initiate an incremental data backup for all user tenants in the cluster.

    obclient [oceanbase]> ALTER SYSTEM BACKUP INCREMENTAL DATABASE;
    

    In this example, after the statement is executed, the system initiates an incremental data backup for the mysql_tenant and oracle_tenant tenants in the cluster.

  • In the sys tenant, initiate an incremental data backup for the mysql_tenant tenant.

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

  • In the sys tenant, initiate a full data backup for the mysql_tenant tenant with the specified backup target path.

    obclient [oceanbase]> ALTER SYSTEM BACKUP TENANT = mysql_tenant TO 'file:///data/backup/one_time_dest';
    

  • In the sys tenant, initiate an incremental data backup for the mysql_tenant tenant with the specified backup target path.

    obclient [oceanbase]> ALTER SYSTEM BACKUP INCREMENTAL TENANT = mysql_tenant TO 'file:///data/backup/one_time_dest';
    

  • In the sys tenant, initiate a full data backup for the mysql_tenant tenant with the specified backup target path and also back up archive logs.

    obclient [oceanbase]> ALTER SYSTEM BACKUP TENANT = mysql_tenant TO 'file:///data/backup/self_contained_dest' PLUS ARCHIVELOG;
    

  • In the sys tenant, initiate an incremental data backup for the mysql_tenant tenant with the specified backup target path and also back up archive logs.

    obclient [oceanbase]> ALTER SYSTEM BACKUP INCREMENTAL TENANT = mysql_tenant TO 'file:///data/backup/self_contained_dest' PLUS ARCHIVELOG;
    

• User tenant

  • In the mysql_tenant tenant, initiate a full data backup for the current tenant.

    obclient [oceanbase]> ALTER SYSTEM BACKUP DATABASE;
    

  • In the oracle_tenant tenant, initiate a full data backup that also backs up archive logs for the current tenant.

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

  • In the mysql_tenant tenant, initiate an incremental data backup for the current tenant.

    obclient [oceanbase]> ALTER SYSTEM BACKUP INCREMENTAL DATABASE;
    

  • In the mysql_tenant tenant, initiate a full data backup for the current tenant with the specified backup target path.

    obclient [oceanbase]> ALTER SYSTEM BACKUP DATABASE TO 'file:///data/backup/one_time_dest';
    

  • In the mysql_tenant tenant, initiate an incremental data backup for the current tenant with the specified backup target path.

    obclient [oceanbase]> ALTER SYSTEM BACKUP INCREMENTAL DATABASE TO 'file:///data/backup/one_time_dest';
    

  • In the mysql_tenant tenant, initiate an incremental data backup for the current tenant with the specified backup target path and also back up archive logs.

    obclient [oceanbase]> ALTER SYSTEM BACKUP INCREMENTAL DATABASE TO 'file:///data/backup/self_contained_dest' PLUS ARCHIVELOG;
    

  • In the mysql_tenant tenant, initiate a full data backup for the current tenant with the specified backup target path and also back up archive logs.

    obclient [oceanbase]> ALTER SYSTEM BACKUP DATABASE TO 'file:///data/backup/self_contained_dest' PLUS ARCHIVELOG;
    

References

• ARCHIVELOG

• Back up to a specified directory

• View the data backup progress

• View the data backup history

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