Spatial Solutions Architect and Database Expert
In this article I am going look at the effect ordinate precision has on the storage space occupied by tables containing sdo_geometry data. In a related article I will also look at the effect storage precision may have on performance (ie searching and returning data in SQL). Sdo_Geometry Coordinate Precision There is a little knownRead More
Today, someone emailed me and asked: I’m using sql developer and oracle spatial to develop my prototype database (I’m really a beginner in SQL), one of my task now is to query parcels (polygon) which crossed by utility pipeline (line) [… and …] to query the intersection point between polygon and line… Can you giveRead More
Recently, like many before me, I had need to create a function that converted a single SDO_GEOMETRY object to GeoJSON. The function I created is below. Note that this function: Does not support attributes (it could do via passing in a refCursor or table of record); Nor does nor does it address how to createRead More
Many people have asked me to convert my Oracle Parallel function to PostGIS. I did it a year or so ago but the results were not as I wished. I have now corrected much that was wrong with the function so I hope it is of more value to those who have asked for itRead More
For users of 10gR2 Locator not licensed for Spatial, the use of sdo_geom.sdo_length is forbidden. So is use of sdo_geom.sdo_length. However, use of sdo_geom.sdo_distance is allowed for Locator users. The sdo_geom.sdo_distance function can be used to construct an sdo_length alternative function that is fully licensed. Here is one such attempt: A quick and simple test.Read More
When creating a new PL/SQL procedure or function, where possible, I write the algorithm in SQL first. Once the SQL is done, it then becomes comparatively easy to encapsulate the SQL in a PL/SQL procedure or function for generic use. This declarative approach is wonderful as the SQL statement can be developed independently of anyRead More
For many years now, I have had an in-database based solution to the exportation of shapefiles. It was this code that provided a base for the work I did on exporting shapefiles from the recently released GeoRaptor 3.0. This exporter package uses GeoTools and JTS, with custom code to enable the exportation of any SQLRead More
I have blogged before on using an external table to load LiDAR data from a CSV file. Today I am going to show how to load Open GeoSpatial Consortium Well Known Text (WKT) spatial data into Oracle. To clean up: This method can be used for any WKT data not just mutli-linestrings. It is aRead More
I always recommend the setting of the layer_gtype property in the parameters of an mdsys.spatial_index. I have entered some details on this in a previous blog article. There has been a change to the supported layer_gtype keywords in 11g with the keywords… LINESTRING MULTILINESTRING … no longer being supported. Now, for linestrings and multi-linestrings (xx02,Read More
UPDATED FUNCTION AT END OF ARTICLE RETURNS SEPARATORS We often have need of string tokenizers in applications. Here is one for Oracle based on work by Pawel Barut. Here are my, simple, tests. Result. token LineString MultiLineString MultiPoint MultiPolygon Point Polygon Result. token The rain in spain stays mainly on the plain Updated Function SometimesRead More