A few years ago I wrote an article about implementing the PostgreSQL function, generate_series, in Oracle. This function is really useful for when trying to write SQL/Functions that can be implemented across one or more databases with reasonable ease. Here is the function implemented in SQL Server 2008: Now, let’s test this function. I hopeRead More
I thought I would publish a simple set of steps that can be followed to restart an Oracle Database after a parameter change causes the database not to open. Here is an example (on Windows). Let’s assume my database (gisdb) currenly has its compatible parameter set to 10.2.0.4. Because I want to test performance atRead More
Data pump is a great utility, more flexible and compatible than the old imp/exp utility. One area where it is useful is in the remapping of tablespaces. I often get data from customers in data pump format in which references to tablespaces that I do not have in my Oracle database exist. But this isRead More
On Tuesday November 11th 2008 I gave a 1 hour presentation on spatial databases entitled An Introduction to Spatial Databases to the Boader and District Spatial Information Group (BADSIG) at Albury NSW. The presentation was rather long as, generally, GIS practitioners are usually unfamiliar with database technology (no fault of their own) and so IRead More
There is a very useful function in PostgreSQL called generate_series that can be used to generate a series of integer numbers from some start value to an end value with an optional step value. Here is the function and its description from the PostgreSQL help. Function Argument Type Return Type Description generate_series(start, stop) int orRead More
Simplifier is a Manifold Map script that implements a set of different methods for topological simplification of a planar-enforced polygon drawing. The code (map file) can be downloaded here To understand what it does see the presentation on Gridding and Simplification (Presentation on techniques for modifing/splitting of large polygons that demonstrate slow performance when beingRead More
This article is not about Oracle Locator/Spatial but simply about the use of some of Oracle’s Relational On-Line Analytical Processing (ROLAP) functionality in building reports for publication with a range of software from Apex to Crystal Reports. The context for this is that I regularly am hirecd to write ordinary financial reports for the DepartmentRead More
I had someone contact me the other day and ask: “I find your articles very helpful and interesting. I was wondering if you can guide me to a link or something that may contain how to figure out surrounding blocks to a given block.” I am assuming that the person wants to know how toRead More
I gave two presentations at the Australian Oracle Spatial Forum held at the Novotel Hotel, Sydney Olympic Park on Thursday 28th August 2008. My two papers were: Automated Layer Management – Experiences At Mid Coast Water Gridding vs Simplification in Extracting Performance from High Density Data The first was co-authored with Mr Brendan Soustal thoughRead More
(WARNING: I have completely re-written my centroid code since this article when I discovered that the algorithm I had been supplied by a Tino failed in one important case. Instead of fixing the existing algorithm I completely re-wrote it and have also added support for polygons and mutil-point geometries. I will edit all centroid relatedRead More