[postgis-users] wrong distance calculation

[Mike Toews]

On 19 March 2015 at 07:55, Ahmet Temiz <ahmettemiz88 at gmail.com> wrote:
>  But then I tried to validate the some results and noticed that spatial query gave
> longer distances than checked values (in QGIS).

Using what projection in QGIS? At what scale? Also, quantify the differences.

On 19 March 2015 at 09:21, Igor Stassiy <istassiy at gmail.com> wrote:
> you are using numeric(10, 2), which trims all except 2 decimal digits. that
> will cause a huge error in calculations.

The distances results from geography are in metres, so 10 cm precision
is more than enough for comparisons between schools and active faults.

-Mike