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谁来帮帮我啊,oracle查询好慢呢

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2016-06-07 14:57:101163browse

求高手不惜赐教,问题是这样的,做一个oracle分页查询,news_data是新闻表,news_type新闻类型,news_image是个新闻图片表,一条新闻可能有多张图片,要求只取一张图片对应一条新闻,然后分页 现在情况是新闻类型多,数据多 这样查询比较慢的,在线等

求高手不惜赐教,问题是这样的,做一个oracle分页查询,news_data是新闻表,news_type新闻类型,news_image是个新闻图片表,一条新闻可能有多张图片,要求只取一张图片对应一条新闻,然后分页 现在情况是新闻类型多,数据多 这样查询比较慢的,在线等啊~~急急急
select *from (select rownum rn,a.* from (select i.img_id,i.img_url,t.news_id,t.news_title,t.news_detail,t.news_date,t.match_type from news_data t left join (select x.img_id,x.news_id,x.img_url from news_image x where not exists(select 1 from news_image y where x.news_id = y.news_id and x.img_id > y.img_id)) i on t.news_id = i.news_id where t.news_type = 3 order by t.news_date desc) a where rownum <= 10 ) where rn > 0
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