| From: | Adam Sah <asah(at)speakeasy(dot)net> | 
|---|---|
| To: | pgsql-performance(at)postgresql(dot)org | 
| Subject: | Re: Problem with large query | 
| Date: | 2004-09-08 14:47:33 | 
| Message-ID: | 413F1B85.9040302@speakeasy.net | 
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| Thread: | |
| Lists: | pgsql-performance | 
by the way, this reminds me: I just ran a performance study at a company doing
    an oracle-to-postgres conversion, and FYI converting from numeric and decimal
    to integer/bigint/real saved roughly 3x on space and 2x on performance.
    Obviously, YMMV.
adam
Tom Lane wrote:
> Marc Cousin <mcousin(at)sigma(dot)fr> writes:
> 
>>I'm having trouble with a (quite big) query, and can't find a way to make it 
>>faster.
> 
> 
> Seems like it might help if the thing could use a HashAggregate instead
> of sort/group.  Numeric is not hashable, so having those TO_NUMBER
> constants in GROUP BY destroys this option instantly ... but why in the
> world are you grouping by constants anyway?  You didn't say what the
> datatypes of the other columns were...
> 
> 			regards, tom lane
> 
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