Every one or two months, someone asks on the PostGIS users list usually somewhat panicked, My geometry is missing when I look in pgAdmin III

This is documented in the PostGIS Frequently Asked questions section of the manual I tried to use PgAdmin to view my geometry column and it is blank, what gives?

Since this …

Read More

If you have a problem that involves finding the things within X distance of other things or finding what things have nothing within X distance do not use ST_Distance for filtering and also do not try to use ST_Intersects + ST_Buffer. Use ST_DWithin instead. Why?

1. ST_DWithin can use an index and ST_Distance can not …

Read More

In mapping frameworks spatial coordinates are often in order of latitude and longitude. In spatial databases spatial coordinates are in x = longitude, and y = latitude.

If you accidentally loaded data as lat,lon, you can always fix the mistake by using the ST_FlipCoordinates function introduced in PostGIS 2.0.

Read More