Re: bad plan

From: Mario Dankoor <m(dot)p(dot)dankoor(at)gmail(dot)com>
To: pgsql-sql(at)postgresql(dot)org
Subject: Re: bad plan
Date: 2012-04-05 12:32:00
Message-ID: 4F7D90C0.3090800@gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-sql

Julien,

I generally try avoid NOT predicates.
If your geo_id is an integer, try geo_id > -1
or if it's a varchar geo_id > ''.
The idea is that geo_id > 0 is false for null values.

I don't think query optimizers are fond of NOT predicates.

SELECT t_geo.frequence
,ST_SetSRID(gc.geom, 4326) as geom
FROM (
SELECT geo_id
,count(*) AS frequence
FROM hit.context_to_context_links
WHERE geo_id > -1
AND taxon_id= ANY (
SELECT taxon_id
FROM rab.ancestors
WHERE ancestors.subphylum_id = 18830
) GROUP BY geo_id
) as t_geo
JOIN hit.geo_candidates gc
ON gc.id = t_geo.geo_id;

On 2012-04-05 2:08 PM, Julien Cigar wrote:
> SELECT
> t_geo.frequence, ST_SetSRID(gc.geom, 4326) as geom
> FROM (
> SELECT
> geo_id , count(*) AS frequence
> FROM
> hit.context_to_context_links
> WHERE
> NOT geo_id IS NULL ANDtaxon_id= ANY (
> SELECT
> taxon_id
> FROM
> rab.ancestors
> WHERE
> ancestors.subphylum_id = 18830
> ) GROUP BY geo_id
> ) as t_geo
> JOIN
> hit.geo_candidates gc ON gc.id = t_geo.geo_id;

In response to

Responses

Browse pgsql-sql by date

  From Date Subject
Next Message Julien Cigar 2012-04-05 12:43:39 Re: bad plan
Previous Message Julien Cigar 2012-04-05 12:08:31 Re: bad plan