Book Image

Practical GIS

Book Image

Practical GIS

Overview of this book

The most commonly used GIS tools automate tasks that were historically done manually—compiling new maps by overlaying one on top of the other or physically cutting maps into pieces representing specific study areas, changing their projection, and getting meaningful results from the various layers by applying mathematical functions and operations. This book is an easy-to-follow guide to use the most matured open source GIS tools for these tasks. We’ll start by setting up the environment for the tools we use in the book. Then you will learn how to work with QGIS in order to generate useful spatial data. You will get to know the basics of queries, data management, and geoprocessing. After that, you will start to practice your knowledge on real-world examples. We will solve various types of geospatial analyses with various methods. We will start with basic GIS problems by imitating the work of an enthusiastic real estate agent, and continue with more advanced, but typical tasks by solving a decision problem. Finally, you will find out how to publish your data (and results) on the web. We will publish our data with QGIS Server and GeoServer, and create a basic web map with the API of the lightweight Leaflet web mapping library.
Table of Contents (22 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Dedication
Preface
14
Appendix

Backing up our data


It's great fun to work with spatial databases. However, when we use a database extensively, we can lose a lot of valuable data in case of a failure. To minimize the damage involved in a server failure, we can, and we should, create backups of our database. In PostgreSQL, there are multiple great and powerful ways to create backups.

Creating static backups

The traditional way of backing up a PostgreSQL database is to create static backups. This method uses the command-line tools pg_dump and pg_restore to create and restore the whole database, or parts of it. Of course, we do not have to use those CLI tools for backing up and restoring, as pgAdmin offers us a way to use of them via its GUI. The main advantage of using static backups is that we can save only parts of the database, like only our spatial data, or just one table. Its main disadvantage, of course, is its static nature. We have to refresh the backups manually if we would like to archive a more recent version of...