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Bigquery 定期合并数据

[英]Bigquery periodically coalesce data

原文 2021-04-03 16:30:14 3 1 google-cloud-platform/ google-bigquery

Assume we have a table in bigquery.假设我们在 bigquery 中有一个表。 and that we stop updating it.并且我们停止更新它。 Will the order on the rows be fixed or will bigquery periodically coalesce the data changing the order?行的顺序是固定的，还是 bigquery 会定期合并更改顺序的数据？ This is a follow up to inquiry about order of rows .这是对行顺序查询的跟进。

1 个解决方案

Coalesce operations only happen (in average) 1 out of 300 times you append data to the table.合并操作仅发生（平均） 1 次 append 数据到表中的 300 次。

In the case where the last append operation you made caused the table to coalesce the data, then that would be the last one;如果您所做的最后一个 append 操作导致表合并数据，那么这将是最后一个； if you stop updating the table after that, BigQuery won't coalesce the data anymore (until you start appending data again).如果您在那之后停止更新表，BigQuery 将不再合并数据（直到您再次开始附加数据）。 If the latest append operation didn't cause a coalesce event, it shouldn't matter also.如果最新的 append 操作没有导致合并事件，那也没有关系。

Either way, I wouldn't rely on the order in which BigQuery stores the data, as it is not designed to be that way.无论哪种方式，我都不会依赖 BigQuery 存储数据的顺序，因为它不是这样设计的。