[GitHub] [doris] big-doudou opened a new issue, #14116: [Problem] 简单SQL在两种写法下，查询速度差异较大。

[GitBox]

big-doudou opened a new issue, #14116:
URL: https://github.com/apache/doris/issues/14116

   ### Search before asking
   
   - [X] I had searched in the 
[issues](https://github.com/apache/incubator-doris/issues?q=is%3Aissue) and 
found no similar issues.
   
   
   ### Version
   
   1.1.3
   
   ### What's Wrong?
   
   数据量一天3000w
   
   SQL A:
   SELECT
       SUM(ad_view)
   FROM
   (
       SELECT
           ad_view
       FROM
            table_a
       WHERE
             dt = 'xxx'
   ) tmp
   sql 执行时间：18s
   
   SQL B:
   SELECT
       sum(ad_view)
   FROM
       table_a
   WHERE
       dt = 'xxx'
   sql 执行时间：0.03s
   
   必现
   1、查看执行计划，两者执行计划差异：SQL A PREAGGREGATION: OFF     SQL B PREAGGREGATION: ON。
   2、SQL A总有一个ScanNode节点 BatchQueueWaitTime: 18s94ms 过长。其他ScanNode节点 
BatchQueueWaitTime: 115.618ms
   3、SQL A更换查询日期分区，BatchQueueWaitTime过长节点会变为另一台机器（排除机器问题）
   
   ### What You Expected?
   
   1、是什么原因导致差异大呢？没有preagg吗？
   2、BatchQueueWaitTime 过大原因是什么呢（是否过多的数据量的scan才会阻塞队列）
   
   ### How to Reproduce?
   
   _No response_
   
   ### Anything Else?
   
   _No response_
   
   ### Are you willing to submit PR?
   
   - [ ] Yes I am willing to submit a PR!
   
   ### Code of Conduct
   
   - [X] I agree to follow this project's [Code of 
Conduct](https://www.apache.org/foundation/policies/conduct)
   


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: commits-unsubscr...@doris.apache.org.apache.org

For queries about this service, please contact Infrastructure at:
us...@infra.apache.org


---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscr...@doris.apache.org
For additional commands, e-mail: commits-h...@doris.apache.org