[postgis-users] Slow Query Times for Split Tiles

[Mateusz Łoskot]

On 1 November 2011 20:23, elliott <elliott at cpi.com> wrote:
> Should splitting raster files into tiles increase query performance?
>
> I have a two 1201x1201 raster tiles that were loaded by the following
> scripts:
>
> raster2pgsql.py -a -r N37E126.hgt -F N37E126 -t srtm3 -s 4326 -k1201x1201 >
> srtm.sql
> psql -f srtm.sql TEST
>
> raster2pgsql.py -a -r N37E127.hgt -F N37E127 -t srtm3 -s 4327 -k50x50 >
> srtm.sql
> psql -f srtm.sql TEST
>
> Querying these raster files appears to produce approximately the same timing
> results.  Should the 50x50 have better performance than the 1201x1201?
> Taking almost 3 minutes to query 10000 points seems to be very slow.

Do you query tiles or points (what points?)?
Do you measure itme of only query only or query and raster blob
processing/rendering?
What's your actual SQL command?

Best regards,
-- 
Mateusz Loskot, http://mateusz.loskot.net
Charter Member of OSGeo, http://osgeo.org
Member of ACCU, http://accu.org