Posts about Spatial

The sheer cleverness of relational databases is often discounted because we so frequently use them for very simple data management tasks.

Serialize an object into a row, store with unique key. yawwwn

Search for unique key, deserialize row into an object. yawwwwwwn

The real power of relational databases is juggling "relations" (aka tables) in large numbers and figuring out on-the-fly the most effective way to filter out rows and find an answer.

PostgreSQL has an undeniably clever query planning system that auto-tunes based on the data in the system. It samples tables to gain statistics about the distribution of data, and uses those statistics to choose the order of joins and filters applied to the data for the most efficient query execution.

Even more amazing, the query planning system is modular enough to integrate user-defined data types, like the geometry

The pg_featureserv micro-service is a thin middleware that binds tables and functions in a PostgreSQL database to a JSON collections API, accessible over HTTP. Using the Crunchy Bridge

PostGIS is one of the most awesome extensions for PostgreSQL and can turn a relational database into a really powerful GIS (Geographic Information System). The PostGIS community is really great about documentation and training

pg_featureserv provides access to the powerful spatial database capabilities of PostGIS and PostgreSQL via a lightweight web service. To do this, it implements the OGC API for Features

The goal of pg_featureserv is to provide easy and efficient access to PostGIS from web clients.

To do this, it uses the emerging OGC API for Features

A community member on the postgis-users mailing list had a question recently:

I have a table of elevation points, and I would like to figure out an elevation profile for a flightline running through those points. How?

This question is a nice showcase of some of my favorite spatial tools

Last month, just under the wire for a 2021 release, the 3.2 version of PostGIS hit the streets! This new PostGIS also supports the latest 3.10 release of GEOS, which underpins a few of the new features.

Raster Algorithms

One of the curious aspects of spatial indexes is that the nodes of the tree can overlap, because the objects being indexed themselves also overlap.

That means that if you're searching an area in which two nodes overlap, you'll have to scan the contents of both nodes. For a trivial example above, that's not a big deal, but if an index has a lot of overlap, the extra work can add up to a measurable query time difference.

The PostGIS spatial index is based on a R-tree

Crunchy Data hosted the third annual PostGIS Day on November 18th.This was our second year with a virtual format and another year of record attendance! We had attendees from more than 99 countries.

PostGIS