我感觉就是考察hive的行转列，列转行。。不知道对不对

INSERT OVERWRITE table dbname.ArticleFeatures PARTITION(dt='{hivevar:job_date}')
SELECT articleid,concat_ws(",",collect_set(A3.url_features))
FROM
(
SELECT
    articleid,concat(A1.url,":",A2.feature) AS url_features
FROM
    (
    select 
    articleid,url 
    from dbname.Articles 
    LATERAL VIEW explode(split(image_urls,",")) tabletest AS url
    )A1
    LEFT JOIN
    dbname.ImageFeatures A2
    ON A1.url=A2.url
)A3
GROUP BY A3.articleid