Troubleshooting skipped or failed dynamic table refreshes¶

跳过刷新¶

动态表按时间表刷新。计划刷新开始时，以下情况可能会导致跳过刷新：

• 如果正在刷新的动态表上游有另一个动态表，而上游的刷新失败或被跳过。

• 如果动态表的上一个刷新仍在运行。

• If the dynamic table's refresh often takes longer than the target lag or there's a significant difference between the target and actual lag, Snowflake might skip a refresh to reduce the rate of future skips.

  For instance, if a dynamic table has a 1-minute target lag but typically takes one hour to refresh, the system adjusts the "actual lag" accordingly.

  要提高刷新性能，请参阅 优化动态表性能。

手动刷新永远不会跳过，但可能会导致跳过其他计划的刷新，特别是在对动态表执行频繁的手动刷新时。这样做会阻止下游动态表刷新。因此，如果某动态表具有根据目标延迟进行刷新的下游动态表，Snowflake 建议您避免频繁地对该动态表执行手动刷新。

Failed refreshes¶

Refresh failures are typically caused by issues with the dynamic table's query definition, input data (for example, parsing errors), or upstream failures.

SELECT
  name,
  data_timestamp,
  state,
  state_code,
  state_message
FROM TABLE(INFORMATION_SCHEMA.DYNAMIC_TABLE_REFRESH_HISTORY(
  NAME_PREFIX => 'MY_DB.MY_SCHEMA',
  ERROR_ONLY => TRUE
));

Diagnose failed refreshes¶

Use the Query Profile to troubleshoot by selecting Show query profile next to each refresh. This shows the execution graph of the query.

Use the Graph view in Snowsight to visualize dependencies. A failed or suspended upstream dynamic table causes its downstream tables to fail. For more information, see 查看连接到动态表的表图形.

SELECT
  timestamp,
  resource_attributes:"snow.executable.name"::VARCHAR AS dt_name,
  resource_attributes:"snow.query.id"::VARCHAR AS query_id,
  value:message::VARCHAR AS error
FROM my_event_table
WHERE
  resource_attributes:"snow.executable.type" = 'DYNAMIC_TABLE' AND
  resource_attributes:"snow.database.name" = 'MY_DB' AND
  value:state = 'FAILED'
ORDER BY timestamp DESC;