Re: 8.2.4 serious slowdown - Mailing list pgsql-general

From Sim Zacks
Subject Re: 8.2.4 serious slowdown
Date
Msg-id fm5n7c$1k87$1@news.hub.org
Whole thread Raw
In response to Re: 8.2.4 serious slowdown  (Bricklen Anderson <banderson@presinet.com>)
List pgsql-general
It does contain a lot more loops, but it is the exact same query, so I don't understand why it would use that kind of
plan

sim

Bricklen Anderson wrote:
> I don't an answer to your question, but an obvious difference is that
> the "slow" query contains many more loops. (this may already have been
> noted, I didn't see it posted however).
>
> (showing just the loops with more than one loop)
>
> ->  Index Scan using assemblies_pkey on assemblies a  (cost=0.00..0.31
> rows=1 width=38) (actual time=0.007..0.009 rows=1 loops=3685)
> ->  Function Scan on stockperowner_lead_ab c  (cost=0.00..15.00 rows=5
> width=20) (actual time=0.012..3.162 rows=1694 loops=3685)
> ->  Index Scan using idx_u_assidpartid on partsassembly b
> (cost=0.00..0.27 rows=1 width=16) (actual time=0.010..0.012 rows=1
> loops=3685)
> ->  Hash Join  (cost=97.69..531.29 rows=1250 width=21) (actual
> time=2.395..78.855 rows=3851 loops=3684)
> ->  Seq Scan on allocatedassemblies b  (cost=0.00..349.62 rows=19062
> width=12) (actual time=0.009..35.493 rows=19062 loops=3684)
> ->  Hash Join  (cost=621.63..1206.10 rows=3854 width=28) (actual
> time=0.074..71.265 rows=593 loops=3684)
> ->  Hash Join  (cost=337.11..839.61 rows=3860 width=32) (actual
> time=0.057..68.467 rows=593 loops=3684)
> ->  Seq Scan on poparts e  (cost=0.00..379.60 rows=16860 width=32)
> (actual time=0.008..34.510 rows=16860 loops=3684)
>
> ---------------------------(end of broadcast)---------------------------
> TIP 2: Don't 'kill -9' the postmaster
>

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