Re: SQL With Dates

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, Apr 20, 2009 at 7:55 AM, Rafael Domiciano
<rafael.domiciano@xxxxxxxxx> wrote:
> Hello People,
>
> I have initiated a work to review the sqls of our internal software.
> Lot of them he problem are about sql logic, or join with table unecessary,
> and so on.
> But software has lot of sql with date, doing thinks like:
> [..]
>   date >= '2009-04-01' AND
>   date <= '2009-04-15'
> [..]
>
> Redoing the SQL with fix date (date = '2009-04-01') o cost in explain always
> still about 200 or less. But with a period the cost is high, about 6000 or
> more.

Yep.  Because you'll be getting more rows. More rows == more cost.  TANSTAAFL.

-- 
Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance


[Postgresql General]     [Postgresql PHP]     [PHP Users]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Yosemite]

  Powered by Linux