by Ben Madin | 31 Oct, 2017 | Database, GIS, PostGIS, PostgreSQL, SQL
Australian postcodes are not reliable nor good indicators of areas, but sometimes, in the absence of any other spatial identifiers, we tend to resort to using them. As we only had a list of centroids for each postcode, to better assess the data we need to create...
by Ben Madin | 29 May, 2017 | Database, PostGIS, PostgreSQL, SQL
Recently we ran into an example of a ‘simple’ query that was doing an immense amount of work. There were a number of reasons behind this, but perhaps the most telling part was the difference between the EXPLAIN (which we routinely run on all system...
by Angus Cameron | 24 Apr, 2016 | GIS, PostgreSQL, SQL
Seaway distance, or the shortest route between two points via water, is an important measure of risk for disease spread between aquaculture establishments. Salmon aquaculture, for example, is usually located in complex fjords, which means that there are numerous...