[postgis-users] CPU tuning

[Olivier Leprêtre]

Well, thanks, could be the explanation.

 

I tried the query but I get SQLSTATE 53200, out of memory after a few seconds.

 

De : postgis-users [mailto:postgis-users-bounces at lists.osgeo.org] De la part de Marcone
Envoyé : lundi 9 janvier 2017 15:31
À : PostGIS Users Discussion
Objet : Re: [postgis-users] CPU tuning

 

 

2017-01-09 12:21 GMT-02:00 Rémi Cura <remi.cura at gmail.com>:

postgres 9.4 is non-parallelised, what you see is that postgres use 100% of a core, but the core beig used is rotated,

which mean the average usage of your cpu is 100% / 4 (your number of core),

which might be the explaination for your 30%.


Exactly! I was write something like this.

 

Please, try the query:

 

FOR row in

            SELECT DISTINCT ON (t_x.code, t_y.code)

                        t_x.code,

                        t_y.code,

                        ST_Distance(t_x.geom, t_y.geom)

            FROM t_x, t_y

            ORDER BY t_x.code,

                        t_y.code,

                        ST_Distance(t_x.geom, t_y.geom)

LOOP

            -- Do something here

END LOOP;


The query above use less conversions, may be more efficient.


 

 



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