Category Blogs

Spatial Data Migration: From Oracle to SQL Server

I spent many years on spatial data modeling and migration on ESRI ArcGIS and ArcSDE, served nature resources sector. Spatial data migration is common when we get involved in map-related applications.

I worked on a project which requested spatial data migration from Oracle to SQL Server. I would like to give you a quick walk-through on how it can be done correctly.

First, let’s introduce some basic concepts:

  • WKT & WKB: Well-known Text & Well-known Binary, text markup language defined by Open Geospatial Consortium (OGC), supported by Oracle 9i+, MS SQL Server 2008 R2+, PostgreSQL PostGIS M2, etc.
  • Geometry & Geography: Geometry: Euclidean (flat) coordinate system; Geography: Round-earth coordinate system.
  • Spatial Data Types: consist of simple types and collection types as illustrated below.

Second...

Read More

Enterprise Integration in a Nutshell

During past two decades, I worked for Oracle, Accenture, Deloitte and involved clients from different industries, including consulting, forestry, finance, healthcare, retails and government agencies, what I observed was their IT environments are more and more complex and expensive, hard to manage and maintain. To simplify IT and reduce cost become strong demands from business.

In enterprise environment, Enterprise Application Integration (EAI) is outstanding since the IT environment is changing quickly with the continuous procurement and integration of new systems. The purpose of this article is to provide the perspectives on middleware selection, approaches and tools, and enterprise integration strategies.

A few key principles of enterprise integration:

  • Build SOA-based IT architecture
  • Choose...
Read More

Generating Data Model using SchemaSpy

Often we need work on existing database schema. How to quickly master the database structure can be a challenge since we might not be able to get the data model ERD diagram from project repository.

However, as long as you get access to the database, then you should be able to generate the data model using SchemaSpy. SchemaSpy is LGPL-based, developed by John Currier in 2004. It has been improved constantly since then.

SchemaSpy is written in Java and deployed as a jar file. Current version is 6.1. It’s a command line tool. The output is a folder with html and other files which outline the database tables, views and their relationships. But before you run, you need have JDBC driver and GraphViz ready...

Read More