在 Snowflake 中有没有办法找出 table 何时被截断？

Question

我搜索了文档并查看了信息模式视图，但是，我不确定如何确定 table 何时被截断，有什么想法吗？

Answer 1

给出几个使用QUERY_HISTORY的例子。信息架构 query_history 是一个 table 函数。

最近 1 小时内的搜索历史以检查被截断的 table -

select query_id,query_text,start_time,end_time from table(information_schema.query_history(dateadd('hours'
,-1,current_timestamp()),
current_timestamp())) where query_text like 'TRUNCATE%test%';

+--------------------------------------+---------------------------+-------------------------------+-------------------------------+
| QUERY_ID                             | QUERY_TEXT                | START_TIME                    | END_TIME                      |
|--------------------------------------+---------------------------+-------------------------------+-------------------------------|
| 01a397da-3200-5a32-0000-00006ca565d1 | TRUNCATE table test_hash; | 2022-04-13 20:38:48.536 -0700 | 2022-04-13 20:38:48.951 -0700 |
+--------------------------------------+---------------------------+-------------------------------+-------------------------------+

下面是将被截断的示例 table -

select count(*) from player;
+----------+
| COUNT(*) |
|----------|
|        4 |
+----------+

发出截断命令 -

truncate table player;
+----------------------------------+
| status                           |
|----------------------------------|
| Statement executed successfully. |
+----------------------------------+

将在 QUERY_HISTORY 中搜索 table 截断。查询是区分大小写的，所以在使用in predicate 进行搜索时需要注意。下面不会给出任何结果，因为我们使用小写查询（截断）

select query_id,query_text,start_time,end_time from table(information_schema.query_history(dateadd('hours'
,-1,current_timestamp()),current_timestamp())) where query_text like 'TRUNCATE%player%';
+----------+------------+------------+----------+
| QUERY_ID | QUERY_TEXT | START_TIME | END_TIME |
|----------+------------+------------+----------|
+----------+------------+------------+----------+

使用小写再次搜索，或者您可以使用函数将 query_text 转换为 lower/upper 并在谓词中给出相同的大小写。例如上（query_text）像'TRUNCATE%PLAYER%'；

select query_id,query_text,start_time,end_time from table(information_schema.query_history(dateadd('hours'
,-1,current_timestamp()),current_timestamp())) where query_text like 'truncate%player%';
+--------------------------------------+------------------------+-------------------------------+-------------------------------+
| QUERY_ID                             | QUERY_TEXT             | START_TIME                    | END_TIME                      |
|--------------------------------------+------------------------+-------------------------------+-------------------------------|
| 01a397e2-3200-5a1a-0000-00006ca5560d | truncate table player; | 2022-04-13 20:46:22.083 -0700 | 2022-04-13 20:46:22.471 -0700 |
+--------------------------------------+------------------------+-------------------------------+-------------------------------+

在 Snowflake 中有没有办法找出 table 何时被截断？

In Snowflake is there a way to find out when a table was truncated?

truncate

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