Book Image

PostGIS Cookbook - Second Edition

By : Pedro Wightman, Bborie Park, Stephen Vincent Mather, Thomas Kraft, Mayra Zurbarán
Book Image

PostGIS Cookbook - Second Edition

By: Pedro Wightman, Bborie Park, Stephen Vincent Mather, Thomas Kraft, Mayra Zurbarán

Overview of this book

PostGIS is a spatial database that integrates the advanced storage and analysis of vector and raster data, and is remarkably flexible and powerful. PostGIS provides support for geographic objects to the PostgreSQL object-relational database and is currently the most popular open source spatial databases. If you want to explore the complete range of PostGIS techniques and expose related extensions, then this book is for you. This book is a comprehensive guide to PostGIS tools and concepts which are required to manage, manipulate, and analyze spatial data in PostGIS. It covers key spatial data manipulation tasks, explaining not only how each task is performed, but also why. It provides practical guidance allowing you to safely take advantage of the advanced technology in PostGIS in order to simplify your spatial database administration tasks. Furthermore, you will learn to take advantage of basic and advanced vector, raster, and routing approaches along with the concepts of data maintenance, optimization, and performance, and will help you to integrate these into a large ecosystem of desktop and web tools. By the end, you will be armed with all the tools and instructions you need to both manage the spatial database system and make better decisions as your project's requirements evolve.
Table of Contents (18 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Setting up the correct data privilege mechanism


PostgreSQL provides a fine-grained privilege system that dictates who can use a particular set of data and how that set of data can be accessed by an approved user. Because of its granular nature, creating an effective set of privileges can be confusing, and may result in undesired behavior. There are different levels of access that can be provided, from controlling who can connect to the database server itself, to who can query a view, to who can execute a PostGIS function.

The challenges of establishing a good set of privileges can be minimized by thinking of the database as an onion. The outermost layer has generic rules and each layer inward applies rules that are more specific than the last. An example of this is a company's database server that only the company's network can access.

Only one of the company's divisions can access database A, which contains a schema for each department. Within one schema, all users can run the SELECT queries...