Oracle Spatial Vector Acceleration: Flick the Switch

Introduction A lot has been written, positive and negative, about the speed of Oracle Spatial over the years, a lot of ill informed (I mean if you don’t use it, how can you criticize it?). But since Oracle Database 12c (12.1) there is no longer any doubt as to the speed of the product. Why?Read More

Geometry object size when exchanging of WKT/WKB encoded geometries.

Introduction The ordinates stored in an geometry objects, across all spatial data types do not have any rounding applied to their values. This is one aspect of data management that is seldom considered by most practitioners. Other articles in this website deal with how to round their values. This article is about a related topic”Read More

Oracle Spatial Mapping and Map Rendering Performance Tips

Comment: This article was written about 10 years ago. Most of what is written is still relevant though the comments about disk usage and access do not apply if SSD is being used. Introduction There are lots of things one can do to improve performance in mapping environments because of a lot of the visualisationRead More

The Frontage Problem: Creating references from land parcel street frontage boundary to point in street

This article demonstrates the power of database-based spatial processing. The business requirement is to determine, dynamically, the side of a land parcel that faces the street (could be single 2 point straight line to something more complex), and then determine the clockface direction from either ends of the frontage or the middle, to a object in the roads reserve (eg telecommunications pit).

Using Oracle’s ST_GEOMETRY type hierarchy with SDO_GEOMETRY: ST_PointN and ST_NumPoints

Oracle Spatial has, for many versions, made available an implementation of the OpenGIS SFS type hierarchy. Today I will show how to use this type hierarchy do extract points from an SDO_GEOMETRY. The first example extracts the first and last point from a linestring constructed from Well Known Text. The second example finds the firstRead More

Scheduling the Export of Spatial Data in Oracle to a Shapefile each night

While there is always a need for software like Safe Software’s Awesome FME to automate import and export tasks from your database, the ability to do so just using Oracle can also be enormously useful. I have implemented the approach described below many times over the years, in different customer sites. At one customer site,Read More

ST_Densify for Object PLSQL

The Java Topology Suite (JTS) has a linestring densifier function that is available in my Spatial Companion for Oracle (SC4O) solution. See here for documentation. For those who aren’t able to install SC4O (some DBAs don’t like it), there was a PL/SQL function in my the old GEOM Package implemetation on this website that allowsRead More

PLSQL ST_AsEWKT and ST_FromWKT Functions For Oracle (any version)

Previously I created the following Java stored procedures to enable the import/export of ZM aware WKT. ST_GeomFromText ST_GeomFromEWKT ST_AsText ST_AsEWKT These functions are necessary if one wishes to exchange geometry data with users of other databases that support WKT functions for 2D, 3D or 4D (ZM). For example, PostGIS supports the EWKT format and providesRead More