다음을 통해 공유

RESTORE

适用于：勾选“是” Databricks SQL 勾选“是” Databricks Runtime

将增量表还原到早期状态。 支持还原到较早的版本号或时间戳。

本页包含有关使用 RESTORE 命令的正确语法的详细信息。 有关使用此命令导航 Delta Lake 表版本的更多指导，请参阅使用 Delta Lake 表历史记录。

语法

RESTORE [ TABLE ] table_name [ TO ] time_travel_version

time_travel_version
 { TIMESTAMP AS OF timestamp_expression |
   VERSION AS OF version }

参数

  • table_name

    标识要还原的 Delta 表。 表单名称不得使用时态规范或选项规范。

  • timestamp_expression 可以是下列项中的任意一项：

    • '2018-10-18T22:15:12.013Z'，即可以强制转换为时间戳的字符串
    • cast('2018-10-18 13:36:32 CEST' as timestamp)
    • '2018-10-18'，即日期字符串
    • current_timestamp() - interval 12 hours
    • date_sub(current_date(), 1)
    • 本身就是时间戳或可强制转换为时间戳的任何其他表达式

  • version 是可以从 DESCRIBE HISTORY table_spec 的输出中获取的 long 值。

timestamp_expression 和 version 都不能是子查询。

示例

-- Restore the employee table to a specific timestamp
> RESTORE TABLE employee TO TIMESTAMP AS OF '2022-08-02 00:00:00';
 table_size_after_restore num_of_files_after_restore num_removed_files num_restored_files removed_files_size restored_files_size
                      100                          3                 1                  0                574                   0

-- Restore the employee table to a specific version number retrieved from DESCRIBE HISTORY employee
> RESTORE TABLE employee TO VERSION AS OF 1;
 table_size_after_restore num_of_files_after_restore num_removed_files num_restored_files removed_files_size restored_files_size
                      100                          3                 1                  0                574                   0

-- Restore the employee table to the state it was in an hour ago
> RESTORE TABLE employee TO TIMESTAMP AS OF current_timestamp() - INTERVAL '1' HOUR;
 table_size_after_restore num_of_files_after_restore num_removed_files num_restored_files removed_files_size restored_files_size
                      100                          3                 1                  0                574                   0