Mysql 蜂巢按播放查找前n页
我们有一个表,希望在其中存储前100页的数据 因此,如果目标表top100页Mysql 蜂巢按播放查找前n页,mysql,hadoop,hive,hiveql,nosql,Mysql,Hadoop,Hive,Hiveql,Nosql,我们有一个表,希望在其中存储前100页的数据 因此,如果目标表top100页 uid string, mid string, pageurl string, plays string, device string 要填写此表,我可以运行: SELECT uid, mid,pageurl,sum(plays),device from $sourceTable where day= $date GROUP BY uid, mid,page url,device; 此查询将提取所有页
uid string,
mid string,
pageurl string,
plays string,
device string
要填写此表,我可以运行:
SELECT uid, mid,pageurl,sum(plays),device from $sourceTable where day= $date GROUP BY uid, mid,page url,device;
此查询将提取所有页面的数据。如何修改此查询,使其仅返回前n页的数据?中描述的LIMIT子句限制结果,但它们是随机选择的
正如您在该链接中所看到的,您可以将reducer限制为1,然后在限制之前应用一个特定的SORT BY子句,以获得与Top N等效的值。这是您想要的吗
select uid, mid, pageurl, sum(plays), device
from $sourceTable
where day = $date
group by uid, mid, page url, device
order by sum(plays)
limit 100;
看起来它将通过配置单元窗口和分析功能解决。还不知道是怎么回事