set hive.auto.convert.join=true;
set hive.mapjoin.smalltable.filesize=300000000;
set hive.auto.convert.join.noconditionaltask=true;
set hive.auto.convert.join.noconditionaltask.size=300000000;

INSERT INTO TABLE ArticleFeatures PARTITION(dt='${etl_dt}')

SELECT articleid AS articleid

              ,concat_ws(',',collect_set(t2.url_feature)) AS url_features

FROM (SELECT DISTINCT

                            articled AS articled

                            ,image_urls AS image_url

             FROM Articles

             LATERAW VIEW explode(splite(image_urls,',')) ) t1

             LEFT JOIN (SELECT url              ON t1.image_url = t2.url

group by articleid

直接手写的没跑过，肯定有问题(PS:我基本每条sql都要测试几遍，很少会有一边通过的样子不知道你们是不是一样)，但是思路基本都是一样的，就是行转列再拼起来。关键是这个调优怎么做，很想知道一下大神的思路

个人调优思路：1、提前去重，减少数据量。数据本身较少，直接使用distinct

                          2、在设置中开启mapjoin，把小表直接加载进内存中join

感觉除此之外没啥要优化的了