Kayla Patel, a member of the city of Boston’s Analytics Team has a three-part write up introducing PostGIS. PostGIS is an open source extender for PostgreSQL. PostGIS extends the capabilities of PostgreSQL, increasing its management capabilities by adding geospatial types and functions to enhance spatial data handled within a relational database structure (more: What is PostGIS?).
The first part of the Introduction to PostGIS series provides an over of the open source software program including how and why to use it, how to use it with Boston’s GIS toolsets, and using it to work with map projections.
Part two reviews how to add and populate a geometry column, checking what the map projection is off a GIS dataset, how to transform a dataset to a different map projection, and how to get X and Y coordinate values from a geometry column.
Part three, entitled “How to get insights from your data”, dives into more advanced functionality of PostGIS. This includes spatial indexing, spatial joins, buffering, finding the nearest, and clustering.
Each concept review in the introduction to PostGIS contains links for further reading and resources.