[postgis-users] How to improve the performance in GIS functions

[Andreas Laggner]

Moin Jose,

first step is done, speed improvement is 80 minutes (87 without GIST and 
7 with). But ArcMap takes 12 seconds. Are there more possible improvements?
My example is:

create table intersect_gf3(gid integer) with oids;
select 
addgeometrycolumn('','intersect_gf3','the_geom','31467','MULTIPOLYGON',2);
insert into intersect_gf3
    select t1.gid,intersection(t1.the_geom, t2.the_geom)
    from gf_veg1 t1, gf_clc t2
    where t1.the_geom && t2.the_geom;

with Corine_GF (750rows) and Atkis_Veg1_GF (6600rows). That is my 
example. In future i want to intersect atkis_germany (7,2 million rows) 
with many other data!

hasta luego      Andreas



Jose Gomez-Dans schrieb:
> Hi Andreas,
>
> On 8/9/07, Andreas Laggner <bloediandi at web.de> wrote:
>   
>> I have to improve the performance from PostGis: LK Gifhorn takes 19
>> seconds in ArcGis and 6 Minutes with PostGis. The intersection InVeKos
>> with Atkis all over lower saxony (niedersachsen) runs since 14 hours
>> now!!! That is overkill. Does someone know how to make PostGis faster in
>> GIS functions?
>>     
>
> You should really specify more clearly what you are trying to do, and
> what sort of data you're using. As a first step, creating and using
> spatial indices  should give you a noticeable speed improvement. Start
> here: <http://postgis.refractions.net/docs/ch03.html#id2684759>.
>
> Good luck!
> Jose
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