From: | Wei Weng <wweng(at)kencast(dot)com> |
---|---|
To: | pgsql-sql(at)postgresql(dot)org |
Subject: | Re: How do I optimize this? |
Date: | 2009-03-17 22:37:05 |
Message-ID: | 49C02611.7020104@kencast.com |
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Thread: | |
Lists: | 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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