Re: [HACKERS] Optimizer badness in 7.0 beta

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От
Peter Eisentraut
Тема
Re: [HACKERS] Optimizer badness in 7.0 beta
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Pine.LNX.4.21.0003051506410.347-100000@localhost.localdomain
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Optimizer badness in 7.0 beta Brian Hirt <bhirt@mobygames.com>
Re: [HACKERS] Optimizer badness in 7.0 beta Tom Lane <tgl@sss.pgh.pa.us>
Re: [HACKERS] Optimizer badness in 7.0 beta Peter Eisentraut <peter_e@gmx.net>
Re: [HACKERS] Optimizer badness in 7.0 beta Brian Hirt <bhirt@mobygames.com>
Re: [HACKERS] Optimizer badness in 7.0 beta Peter Eisentraut <e99re41@DoCS.UU.SE>
Re: [HACKERS] Optimizer badness in 7.0 beta Tom Lane <tgl@sss.pgh.pa.us>
This query can be rewritten as

SELECT creation_timestamp, etc. 
FROM game, game_developer
WHERE game.game_id = game_developer.game_id AND approved = 1 AND developer_id = 3
ORDER BY copyright_year desc, game_title

The way you're writing it you're almost asking it to be slow. :)

Of course that still doesn't explain why it's now 94sec versus formerly 1
but I'm sure Tom Lane will enlighten us all very soon. :)


Brian Hirt writes:

> select 
> 	creation_timestamp,
[snip]
> from 
> 	game 
> where 
> 	approved = 1 
> and 
> 	game_id in (
> 		select 
> 			distinct game_id
> 		from 
> 			game_developer
> 		where 
> 			developer_id = 3) 
> order by 
> 	copyright_year desc,
> 	game_title;


-- 
Peter Eisentraut                  Sernanders väg 10:115
peter_e@gmx.net                   75262 Uppsala
http://yi.org/peter-e/            Sweden



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