Re: Very slow running query PostgreSQL 9.3.4

2014-08-29 7:28 GMT+03:00 Burgess, Freddie <FBurgess(at)radiantblue(dot)com>:

> -> Index Scan using idx_clone_report_query_y201408 on
> SARS_IMPACT_REPORT_y2014m08 this__2 (cost=0.57..5570.95 rows=103
> width=136) (actual time=8.300..33308.118 rows=710202 loops=1)
> Index Cond: ((model_uid = 1::bigint) AND
> (source_date_time >= '2014-08-08 19:21:08.212'::timestamp without time
> zone) AND (source_date_time <= '2014-08-09 03:59:19.388'::timestamp without
> time zone))
> Filter: ((clone_location &&
> '010300000001000000050000006787D1E89889F5BFFBA6BE01196EE53F1AF703F9588EF5BF6D9AC3A07D5FE53F0C2792E0B193F5BF6D9AC3A07D5FE53FC096C4F07198F5BFFBA6BE01196EE53F6787D1E89889F5BFFBA6BE01196EE53F'::geometry)
>
> AND
> _st_contains('010300000001000000050000006787D1E89889F5BFFBA6BE01196EE53F1AF703F9588EF5BF6D9AC3A07D5FE53F0C2792E0B193F5BF6D9AC3A07D5FE53FC096C4F07198F5BFFBA6BE01196EE53F6787D1E89889F5BFFBA6BE01196EE53F'::geometry,
> clone_location)
> OR _st_touches (clone_location,
> '010300000001000000050000006787D1E89889F5BFFBA6BE01196EE53F1AF703F9588EF5BF6D9AC3A07D5FE53F0C2792E0B193F5BF6D9AC3A07D5FE53FC096C4F07198F5BFFBA6BE01196EE53F6787D1E89889F5BFFBA6BE01196EE53F'::geometry)))
> Rows Removed by Filter: 912821
>

First, I think your stats are off, note this line:

-> Index Scan using idx_clone_report_query_y201408 on
SARS_IMPACT_REPORT_y2014m08 this__2 (cost=0.57..5570.95 >>>rows=103<<<
width=136) (actual time=8.300..33308.118 >>>rows=710202<<< loops=1)

Real rows returned are 3 orders of magnituded higher then expected.

Also, given almost a million rows were removed by the filter, it'd be worth
trying to select on `clone_location` first.

Could you do the following:

VACUUM ANALYZE sars_impact_report_y2014m08;
VACUUM ANALYZE sars_impact_report;
explain (analyze, buffers)
WITH clone AS (
SELECT * FROM SARS_IMPACT_REPORT
WHERE
ST_within(this_.clone_location,'010300000001000000050000006787D1E89889F5BFFBA6BE01196EE53F1AF703F9588EF5BF6D9AC3A07D5FE53F0C2792E0B193F5BF6D9AC3A07D5FE53FC096C4F07198F5BFFBA6BE01196EE53F6787D1E89889F5BFFBA6BE01196EE53F')
OR ST_touches
(this_.clone_location,'010300000001000000050000006787D1E89889F5BFFBA6BE01196EE53F1AF703F9588EF5BF6D9AC3A07D5FE53F0C2792E0B193F5BF6D9AC3A07D5FE53FC096C4F07198F5BFFBA6BE01196EE53F6787D1E89889F5BFFBA6BE01196EE53F')
)
select * from clone this_
where this_.model_uid=1
and this_.source_date_time between '2014-08-08 19:21:08.212'::timestamp
without time zone and '2014-08-09 03:59:19.388'::timestamp without time
zone
order by source_date_time asc, source_uid asc, clone_report_uid
limit 3000;

--
Victor Y. Yegorov