如何通过查询获取 Redshift 中查询的总运行时间？

Question

我正在对 redshift 中的一些查询进行基准测试，以便我可以对我对表所做的更改做出一些明智的判断，例如添加编码和运行真空。我可以使用 LIKE 子句查询

stl_query

表来查找我感兴趣的查询，因此我有查询 id，但是像

stv_query_summary

这样的表/视图太细粒度了，我不是确定如何生成我需要的摘要！

GUI仪表板显示了我感兴趣的指标，但格式很难存储以供以后分析/比较（换句话说，我想避免截图）。有没有一种好的方法可以使用 sql selects 重建该视图？

Answer 1

为了补充Alex的答案，我想评论一下stl_query表有一个不便之处，如果查询在运行时之前位于队列中，那么队列时间将包含在运行时中，因此运行时不会很好查询的性能指标。

要了解查询的实际运行时间，请检查 stl_wlm_query 的total_exec_time。

select total_exec_time
from stl_wlm_query
where query='query_id'

Answer 2

https://github.com/awslabs/amazon-redshift-utils有一些有用的工具/脚本

这里是其中一个被删除的脚本，为您提供以毫秒为单位的查询运行时间。使用过滤器、排序等来显示您正在寻找的结果：

select userid, label, stl_query.query, trim(database) as database, trim(querytxt) as qrytext, starttime, endtime, datediff(milliseconds, starttime,endtime)::numeric(12,2) as run_milliseconds, 
       aborted, decode(alrt.event,'Very selective query filter','Filter','Scanned a large number of deleted rows','Deleted','Nested Loop Join in the query plan','Nested Loop','Distributed a large number of rows across the network','Distributed','Broadcasted a large number of rows across the network','Broadcast','Missing query planner statistics','Stats',alrt.event) as event
from stl_query 
left outer join ( select query, trim(split_part(event,':',1)) as event from STL_ALERT_EVENT_LOG group by query, trim(split_part(event,':',1)) ) as alrt on alrt.query = stl_query.query
where userid <> 1 
-- and (querytxt like 'SELECT%' or querytxt like 'select%' ) 
-- and database = ''
order by starttime desc
limit 100

Answer 3

SELECT user_id,
       query_id,
       transaction_id,
       session_id,
       status,
       trim(database_name) AS database_name,
       start_time,
       end_time,
       result_cache_hit,
       elapsed_time,
       queue_time,
       execution_time,
       planning_time,
       trim(query_text) as query_text,
       query_label
FROM sys_query_history
WHERE query_type = 'SELECT'
AND query_label = 'Monday'
AND result_cache_hit = 'false'
ORDER BY start_time DESC limit 10