手动刷新动态表

You can manually refresh a dynamic table to include the latest data without waiting for the next scheduled refresh. This is useful for one-time updates or when a table has a large target lag and the next refresh occurs much later.

小技巧

避免对具有下游动态表的动态表频繁执行手动刷新，这些下游动态表会根据目标延迟自动刷新。这类手动刷新可能会导致计划的刷新跳过，并阻止下游表更新。

To manually refresh, use the ALTER DYNAMIC TABLE ... REFRESH command or Snowsight as shown in the following steps:

ALTER DYNAMIC TABLE my_dynamic_table REFRESH
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对于需要精确刷新时间的情况，例如使刷新与外部系统计划或批处理窗口保持一致时，您可以使用带有 CRON 表达式的任务来触发刷新。

例如：

-- Create the task
CREATE TASK my_dt_refresh_task
  WAREHOUSE = my_wh
  SCHEDULE = 'USING CRON 0 0 * * * America/Los_Angeles' -- Example: daily at midnight PST
  COMMENT = 'Daily 5pm PT manual refresh of my_dynamic_table'
  AS
    ALTER DYNAMIC TABLE my_dynamic_table REFRESH;

-- Enable the task
ALTER TASK my_dt_refresh_task RESUME;

-- Show the task
SHOW TASKS LIKE 'my_dt_refresh_task';
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+------------+-----------------+-------------------------------------+---------------+-------------+--------------+-------------------------------------------------+-----------|-------------------------------------------+------------------+---------+----------------------------------------------+-----------+-----------------------------+-------------------+-------------------------------|-------------------+-----------------+--------+---------------------+-----------------------+---------------------+-----------------+----------------------------+-----------------+
| CREATED_ON | NAME            | ID                                  | DATABASE_NAME | SCHEMA_NAME | OWNER        | COMMENT                                         | WAREHOUSE | SCHEDULE                                  | [ ] PREDECESSORS | STATE   | DEFINITION                                   | CONDITION | ALLOW_OVERLAPPING_EXECUTION | ERROR_INTEGRATION | LAST_COMMITTED_ON             | LAST_SUSPENDED_ON | OWNER_ROLE_TYPE | CONFIG | TASK_RELATIONS      | LAST_SUSPENDED_REASON | SUCCESS_INTEGRATION | SCHEDULING_MODE | TARGET_COMPLETION_INTERVAL | EXECUTE_AS_USER |
|------------+-----------------+-------------------------------------+---------------+-------------+--------------+-------------------------------------------------+-----------+-------------------------------------------+------------------+---------+----------------------------------------------+-----------+-----------------------------+-------------------+-------------------------------+-------------------+-----------------+--------+---------------------+-----------------------+---------------------+-----------------+----------------------------+-----------------|
| 2025-10-02 | DT_REFRESH_TASK | 01bf6f0d-690f-f373-0000-000000025e3d| mydb          | my_schema   | ACCOUNTADMIN | Daily 5pm PT manual refresh of my_dynamic_table | mywh      | USING CRON 0 17 * * * America/Los_Angeles | []               | Started | ALTER DYNAMIC TABLE my_dynamic_table REFRESH | null      | false                       | null              | 2025-10-02 05:08:52.897 +0000 | null              | ROLE            | null   | {"Predecessors":[]} | null                  | null                | null            | null                       | null            |
+------------+-----------------+-------------------------------------+---------------+-------------+--------------+-------------------------------------------------+-----------|-------------------------------------------+------------------+---------+----------------------------------------------+-----------+-----------------------------+-------------------+-------------------------------|-------------------+-----------------+--------+---------------------+-----------------------+---------------------+-----------------+----------------------------+-----------------+

在大多数情况下，Snowflake 建议使用目标滞后，这样可以优化刷新频率，并相比固定 CRON 计划（可能会进行不必要的运行）可以降低成本。

语言: 中文