Articles

Converting PostgreSQL Native Geometric Types to PostGIS

Introduction I comes as a surprise to some that PostgreSQL has it own native geometric type system. The geometric types are documented here but the list includes: point – Point on a plane – (x,y) lseg – Finite line segment – ((x1,y1),(x2,y2)) box – Rectangular box – ((x1,y1),(x2,y2)) path – Closed path (similar to polygon)Read More

Creating linestring geometries from a table of ordinates (Oracle)

Introduction (This article is about Oracle Spatial.) It is quite a common thing to have ordinates held as separate columns within a table as in the following CTE example. with cte as ( select 001 as asset_id, 1 as part_num,1 as vertex_num,0 as x,5 as y, 0 as m from dual union all select 001Read More