Date: Thu, 07 Nov 2002 01:44:25 +0900
From: Masaru Sugawara <rk73@sea.plala.or.jp>
To: <terry@ashtonwoodshomes.com>
Subject: Re: query optimization question
Cc: pgsql-sql@postgresql.org
In-Reply-To: <002601c2859d$0d825480$2766f30a@development.greatgulfhomes.com>
References: <002601c2859d$0d825480$2766f30a@development.greatgulfhomes.com>
Errors-To: rk73@sea.plala.or.jp
Message-Id: <20021107014333.F0D0.RK73@sea.plala.or.jp>
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
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On Wed, 6 Nov 2002 09:01:49 -0500
<terry@ashtonwoodshomes.com> wrote:

> If anyone can see a way to do a group by to do this, then I will be happy to
> hear about it, because currently the resultset has to do a separate
> (sequential or index) scan of the deficiencies table.  The only way I can
> see to do a group by would be to break out the aging categories into
> separate queries, but that wins me nothing because each query then does its
> own scan...
> 
> The expected simplified output of this query looks like this:
> Project	<30 	30-60 	>=60	lot total	<30	30-60	>=60	def total
> X	1	2	1	4	5	10	5	20	(if X had 4 lots, each of 5 deficiencies)
> Y	1	1	0	2	3	3	0	6	(each has eg 3 deficiencies in project Y)
> 


The following query may be one of the ways, but I cannot confirm whether
it goes well or not. 


SELECT
    project_id,
    marketing_name,
    COUNT(lots.lot_id) AS def_count,
    COUNT(CASE WHEN dt.days_old_start_date < {d '2002-10-07'}
                          THEN lots.lot_id ELSE NULL END) AS def_count_less_30,
    COUNT(CASE WHEN dt.days_old_start_date >= {d '2002-10-07'}
                            AND dt.days_old_start_date < {d '2002-09-07'}
                          THEN lots.lot_id ELSE NULL END) AS def_count_30_60,
    COUNT(CASE WHEN dt.days_old_start_date >= {d '2002-09-07'}
                            AND dt.days_old_start_date < {d '2002-08-08'}
                          THEN lots.lot_id ELSE NULL END) AS def_count_60_90,
    COUNT(CASE WHEN dt.days_old_start_date >= {d '2002-08-08'}
                          THEN lots.lot_id ELSE NULL END) AS def_count_greater_90,
    COUNT(DISTINCT(CASE WHEN
                                   dt.days_old_start_date < {d '2002-10-07'}
                          THEN lots.lot_id ELSE NULL END )) AS lot_count_less_30,
   COUNT(DISTINCT(CASE WHEN
                                   dt.days_old_start_date >= {d '2002-10-07'}
                           AND dt.days_old_start_date < {d '2002-09-07'}
                          THEN lots.lot_id ELSE NULL END )) AS lot_count_30_60,
   COUNT(DISTINCT(CASE WHEN
                                   dt.days_old_start_date >= {d '2002-09-07'}
                           AND dt.days_old_start_date < {d '2002-08-08'}
                          THEN lots.lot_id ELSE NULL END )) AS lot_count_60_90,
   COUNT(DISTINCT(CASE WHEN
                                  dt.days_old_start_date >= {d '2002-08-08'}
                          THEN lots.lot_id ELSE NULL END )) AS lot_count_greater_90,
   COUNT(DISTINCT lots.lot_id) AS lot_count
FROM
   (SELECT * FROM deficiency_table
               WHERE assigned_supplier_id = '101690') AS dt,
   (SELECT * FROM deficiency_status,
               WHERE ds.is_outstanding) AS ds,
   (SELECT * FROM projects
               WHERE proj.division_id = 'GGH') AS proj
   lots
WHERE
   dt.lot_id = lots.lot_id
   AND lots.division_id = proj.division_id
   AND lots.project_id = proj.project_id
   AND dt.deficiency_status_id = ds.deficiency_status_id
   AND NOT EXISTS
          (SELECT 1 FROM menu_group_projects
             WHERE menu_code = 'WA'
                 AND division_id = proj.division_id
                 AND project_id = proj.project_id
                 AND status = 'I')
ORDER BY proj.project_id


Regards,
Masaru Sugawara