Re: How do I optimize this?

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От Wei Weng
Тема Re: How do I optimize this?
Дата
Msg-id 49C02611.7020104@kencast.com
обсуждение исходный текст
Ответ на How do I optimize this?  (Wei Weng <wweng@kencast.com>)
Ответы Re: How do I optimize this?  (Richard Huxton <dev@archonet.com>)
Список pgsql-sql
I made a mistake in the queries:

They should be

update T set t1 = b.aa FROM (select COUNT(1) as aa FROM D WHERE D.da = 
1) as b where tkey = <value>;
update T set t2 = b.aa FROM (select COUNT(1) as aa FROM D WHERE D.da = 
2) as b where tkey = <value>;
...
update T set t10 = b.aa FROM (select COUNT(1) as aa FROM D WHERE D.da = 
10) as b where tkey = <value>;

Thanks
Wei

On 03/17/2009 05:43 PM, Wei Weng wrote:
> Hi all.
>
> I have the following scenario:
>
> A table T (int t1; int t2; ... int t10; int tkey)
> A table D (int da; int db),
>
> And I have the following query
> update T set t1 = b.aa FROM (select COUNT(1) as aa FROM D WHERE D.da = 
> <count>) as b where tkey = <value>;
> update T set t2 = b.aa FROM (select COUNT(1) as aa FROM D WHERE D.da = 
> <count>) as b where tkey = <value>;
> ...
> update T set t10 = b.aa FROM (select COUNT(1) as aa FROM D WHERE D.da 
> = <count>) as b where tkey = <value>;
>
> The queries are run on the same <value>. Is there anyway to optimize 
> this???
>
>
> Thanks
> Wei
>
>
>
>


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