On Wed, 2007-09-12 at 10:15 +0800, El-Lotso wrote:
> I'm downgrading to 8.1.9 to see if it helps too.\
Nope : Doesn't help at all.. the number of rows at the nested loop and
hash joins are still 1 to 500 ratio. This plan is slightly different in
that PG is choosing seq_scans
Nested Loop Left Join (cost=2604.28..4135.15 rows=1 width=59) (actual time=249.973..15778.157 rows=528 loops=1)
Join Filter: ((("inner".id)::text = ("outer".id)::text) AND ("inner".hid = "outer".hid) AND ("inner".seq_time = "outer".seq_time) AND ("inner".seq_date = "outer".seq_date))
-> Nested Loop Left Join (cost=1400.08..2766.23 rows=1 width=67) (actual time=168.375..8002.573 rows=528 loops=1)
Join Filter: ((("inner".id)::text = ("outer".id)::text) AND ("inner".hid = "outer".hid) AND ("inner".seq_time = "outer".seq_time) AND ("inner".seq_date = "outer".seq_date))
-> Hash Join (cost=127.25..1328.68 rows=1 width=59) (actual time=74.195..84.855 rows=528 loops=1)
Hash Cond: ((("outer".id)::text = ("inner".id)::text) AND ("outer".ttype = "inner".ttype) AND ("outer".start_timestamp = "inner".start_timestamp))
-> Seq Scan on trh (cost=0.00..1060.18 rows=9416 width=36) (actual time=0.022..53.830 rows=9416 loops=1)
Filter: ((ttype = 35) OR (ttype = 75) OR (ttype = 703) OR (ttype = 740) OR (ttype = 764))
-> Hash (cost=125.53..125.53 rows=230 width=63) (actual time=12.487..12.487 rows=192 loops=1)
-> Hash Join (cost=18.69..125.53 rows=230 width=63) (actual time=11.043..12.007 rows=192 loops=1)
Hash Cond: (("outer".id)::text = ("inner".id)::text)
-> Seq Scan on ts (cost=0.00..87.36 rows=3436 width=40) (actual time=0.003..5.436 rows=3436 loops=1)
-> Hash (cost=18.57..18.57 rows=48 width=23) (actual time=0.876..0.876 rows=48 loops=1)
-> Seq Scan on d (cost=0.00..18.57 rows=48 width=23) (actual time=0.019..0.771 rows=48 loops=1)
Filter: ((record_update_date_time >= '2007-08-20 00:00:00'::timestamp without time zone) AND (record_update_date_time <= '2007-09-08 00:00:00'::timestamp without time zone) AND ((code)::text = 'HUA75'::text))
-> Hash Join (cost=1272.83..1437.52 rows=1 width=61) (actual time=11.784..14.216 rows=504 loops=528)
Hash Cond: ((("outer".id)::text = ("inner".id)::text) AND ("outer".ttype = "inner".ttype) AND ("outer".start_timestamp = "inner".start_timestamp))
-> Seq Scan on ts (cost=0.00..87.36 rows=3436 width=40) (actual time=0.003..5.744 rows=3436 loops=528)
-> Hash (cost=1268.29..1268.29 rows=606 width=59) (actual time=82.783..82.783 rows=504 loops=1)
-> Hash Join (cost=18.69..1268.29 rows=606 width=59) (actual time=76.454..81.515 rows=504 loops=1)
Hash Cond: (("outer".id)::text = ("inner".id)::text)
-> Seq Scan on trh (cost=0.00..1198.22 rows=9064 width=36) (actual time=0.051..66.555 rows=9064 loops=1)
Filter: ((ttype = 69) OR (ttype = 178) OR (ttype = 198) OR (ttype = 704) OR (ttype = 757) OR (ttype = 741) OR (ttype = 765))
-> Hash (cost=18.57..18.57 rows=48 width=23) (actual time=0.863..0.863 rows=48 loops=1)
-> Seq Scan on d (cost=0.00..18.57 rows=48 width=23) (actual time=0.019..0.761 rows=48 loops=1)
Filter: ((record_update_date_time >= '2007-08-20 00:00:00'::timestamp without time zone) AND (record_update_date_time <= '2007-09-08 00:00:00'::timestamp without time zone) AND ((code)::text = 'HUA75'::text))
-> Hash Join (cost=1204.20..1368.89 rows=1 width=61) (actual time=11.498..13.941 rows=504 loops=528)
Hash Cond: ((("outer".id)::text = ("inner".id)::text) AND ("outer".ttype = "inner".ttype) AND ("outer".start_timestamp = "inner".start_timestamp))
-> Seq Scan on ts (cost=0.00..87.36 rows=3436 width=40) (actual time=0.003..5.593 rows=3436 loops=528)
-> Hash (cost=1199.62..1199.62 rows=610 width=59) (actual time=70.186..70.186 rows=504 loops=1)
-> Hash Join (cost=18.69..1199.62 rows=610 width=59) (actual time=64.270..68.886 rows=504 loops=1)
Hash Cond: (("outer".id)::text = ("inner".id)::text)
-> Seq Scan on trh (cost=0.00..1129.20 rows=9128 width=36) (actual time=0.020..54.050 rows=9128 loops=1)
Filter: ((ttype = 177) OR (ttype = 197) OR (ttype = 705) OR (ttype = 742) OR (ttype = 758) OR (ttype = 766))
-> Hash (cost=18.57..18.57 rows=48 width=23) (actual time=1.100..1.100 rows=48 loops=1)
-> Seq Scan on d (cost=0.00..18.57 rows=48 width=23) (actual time=0.019..0.994 rows=48 loops=1)
Filter: ((record_update_date_time >= '2007-08-20 00:00:00'::timestamp without time zone) AND (record_update_date_time <= '2007-09-08 00:00:00'::timestamp without time zone) AND ((code)::text = 'HUA75'::text))
Total runtime: 15779.769 ms
Am I screwed? Is a schema redesign really a necessity? This would be a
real pain given the rewrite of _all_ the queries and can't maintain
compatibility in the front-end app between sql server and PG.
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