Re: query optimization question

On Wed, 6 Nov 2002 09:01:49 -0500
<terry(at)ashtonwoodshomes(dot)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