From: "Dave Dutcher" <dave@tridecap.com>
To: "'Mario Splivalo'" <msplival@jagor.srce.hr>,
	<pgsql-performance@postgresql.org>
Subject: Re: Lot'sa joins - performance tip-up, please?
Date: Wed, 3 May 2006 10:20:35 -0500
Message-ID: <003001c66ec5$205a0160$8300a8c0@tridecap.com>
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>          ->  Nested Loop  (cost=0.00..176144.30 rows=57925 width=26)
> (actual time=68.322..529472.026 rows=57925 loops=1)
>                ->  Seq Scan on ticketing_codes_played
> (cost=0.00..863.25 rows=57925 width=8) (actual time=0.042..473.881
> rows=57925 loops=1)
>                ->  Index Scan using ticketing_codes_pk on
> ticketing_codes  (cost=0.00..3.01 rows=1 width=18) (actual
> time=9.102..9.108 rows=1 loops=57925)
>                      Index Cond: (ticketing_codes.code_id =
> "outer".code_id)
>  Total runtime: 542000.093 ms
> (27 rows)
> 
> 
> I'll be more than happy to provide any additional information 
> that I may
> be able to gather. I'd be most happy if someone would scream something
> like "four joins, smells like a poor design" because design 
> is poor, but
> the system is in production, and I have to bare with it.


It looks like that nested loop which is joining ticketing_codes_played
to ticketing_codes is the slow part.  I'm curious how many rows are in
the ticketing_codes table?

Four or five joins does not seem like a lot to me, but it can be slow if
you are joining big tables with other big tables.