postgresql date filed query performance - postgresql

Question

i have two table . news table have 7m record and news_publish table have 70m record
when i execute this query took enormous amounts of time and very slow .
i add three index for tuning but query is slow.
when i google this problem i found that someone suggest that change statistics to 1000 and i chage it ,but problem is yet
alter table khb_news alter submitteddate set statistics 1000;
SELECT n.id as newsid ,n.title,p.submitteddate as publishdate,
n.summary ,n.smallImageid ,
n.classification ,n.submitteddate as newsdate,
p.toorganizationid
from khb_news n
join khb_news_publish p
on n.id=p.newsid
left join dataitem b on b.id=n.classification
where
n.classification in (1) and n.newstype=60
AND n.submitteddate >= '2014/06/01'::timestamp AND n.submitteddate <'2014/08/01'::timestamp and p.toorganizationid=123123
order by p.id desc
limit 10 offset 0
indexes is :
CREATE INDEX "p.id"
ON khb_news_publish
USING btree
(id DESC);
CREATE INDEX idx_toorganization
ON khb_news_publish
USING btree
(toorganizationid);
CREATE INDEX "idx_n.classification_n.newstype_n.submitteddate"
ON khb_news
USING btree
(classification, newstype, submitteddate);
after add this indexes and run explain analyze i get this explain
"Limit (cost=0.99..10100.13 rows=10 width=284) (actual time=24711.831..24712.849 rows=10 loops=1)"
" -> Nested Loop (cost=0.99..5946373.12 rows=5888 width=284) (actual time=24711.827..24712.837 rows=10 loops=1)"
" -> Index Scan using "p.id" on khb_news_publish p (cost=0.56..4748906.31 rows=380294 width=32) (actual time=2.068..23338.731 rows=194209 loops=1)"
" Filter: (toorganizationid = 95607)"
" Rows Removed by Filter: 36333074"
" -> Index Scan using khb_news_pkey on khb_news n (cost=0.43..3.14 rows=1 width=260) (actual time=0.006..0.006 rows=0 loops=194209)"
" Index Cond: (id = p.newsid)"
" Filter: ((submitteddate >= '2014-06-01 00:00:00'::timestamp without time zone) AND (submitteddate < '2014-08-01 00:00:00'::timestamp without time zone) AND (newstype = 60) AND (classification = ANY ('{19,20,21}'::bigint[])))"
" Rows Removed by Filter: 1"
"Planning time: 3.871 ms"
"Execution time: 24712.982 ms"
i add explain in https://explain.depesz.com/s/Gym
how can change query to make it faster ??

Answer 1

You should start with creating an index on khb_news_publish(toorganizationid, id)
CREATE INDEX idx_toorganization_id
ON khb_news_publish
USING btree
(toorganizationid, id);
This should fix the problem but you might also need index:
CREATE INDEX idx_id_classification_newstype_submitteddate
ON khb_news
USING btree
(classification, newstype, submitteddate, id);