SHOW RESTORE PREVIEW

描述

该语句用于展示恢复到指定时间所需的数据备份集（backup_set）和日志归档（archivelog_piece）。

使用限制及注意事项

必须在 ALTER SYSTEM RESTORE...PREVIEW 命令执行成功后，再执行该命令，否则无法获取所需的结果。

权限要求

执行该语句需要当前用户拥有 ALTER SYSTEM 权限。

语法

SHOW RESTORE PREVIEW;

示例

1. 指定原始数据备份路径和日志归档路径，并且期望恢复到指定时间戳 2024-04-09 16:15:54。

   ALTER SYSTEM RESTORE FROM 'file:///ob_backup/data, file:///ob_backup/archive' UNTIL TIME = '2024-04-09 16:15:54' PREVIEW;
   

2. 展示恢复到指定时间所需的 backup_set 和 archivelog_piece。

   SHOW RESTORE PREVIEW;
   

   返回结果如下：

   +--------------+-----------+--------------------------------------------------------------------------------+------------------------------------------------------------------------------+
   | backup_type  | backup_id | backup_dest                                                                    | description                                                                  |
   +--------------+-----------+--------------------------------------------------------------------------------+------------------------------------------------------------------------------+
   | BACKUP_SET   |         1 | file:///ob_backup/data/backup_set_1_full |                                                                              |
   | BACKUP_PIECE |         1 | file:///ob_backup/archive/piece_d1002r1p1 | start_scn_display: 20240409T155954, checkpoint_scn_display: 20240409T160154. |
   | BACKUP_PIECE |         2 | file:///ob_backup/archive/piece_d1002r1p2 | start_scn_display: 20240409T160154, checkpoint_scn_display: 20240409T160353. |
   | BACKUP_PIECE |         3 | file:///ob_backup/archive/piece_d1002r1p3 | start_scn_display: 20240409T160354, checkpoint_scn_display: 20240409T160553. |
   | BACKUP_PIECE |         4 | file:///ob_backup/archive/piece_d1002r1p4 | start_scn_display: 20240409T160554, checkpoint_scn_display: 20240409T160754. |
   | BACKUP_PIECE |         5 | file:///ob_backup/archive/piece_d1002r1p5 | start_scn_display: 20240409T160754, checkpoint_scn_display: 20240409T160953. |
   | BACKUP_PIECE |         6 | file:///ob_backup/archive/piece_d1002r1p6 | start_scn_display: 20240409T160954, checkpoint_scn_display: 20240409T161154. |
   | BACKUP_PIECE |         7 | file:///ob_backup/archive/piece_d1002r1p7 | start_scn_display: 20240409T161154, checkpoint_scn_display: 20240409T161354. |
   | BACKUP_PIECE |         8 | file:///ob_backup/archive/piece_d1002r1p8 | start_scn_display: 20240409T161354, checkpoint_scn_display: 20240409T161554. |
   +--------------+-----------+--------------------------------------------------------------------------------+------------------------------------------------------------------------------+
   9 rows in set
   

   查询结果中展示了恢复到指定时间所需的所有 backup_set 和 archivelog_piece，以及这些文件在原始数据备份和日志归档目的端下的存放路径。如果因为业务需要，您已将部分或所有文件手动转移到其他路径或存储介质上，则需要您根据实际情况，自行维护好每个 backup_set 和 archivelog_piece 从原始路径到当前路径之间的映射关系。

   例如，上述查询结果中，需要使用 BACKUP_PIECE 为 1 的 archivelog_piece 进行恢复，而该文件已经被手动转移到 oss://test_bucket/archive/piece_1 上，则在使用 ADD RESTORE SOURCE 命令加载备份路径时，需要选择新的存放路径 oss://test_bucket/archive/piece_1。

相关文档

• RESTORE PREVIEW
• 执行指定路径的恢复