Simple Killer Queries

Simple Killer Queries

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...
Seaway distances with PostgreSQL

Seaway distances with PostgreSQL

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...
Temporo-spatial visualisation of disease outbreaks

Temporo-spatial visualisation of disease outbreaks

In epidemiology, analysis of data by space (mapping) and by time (e.g. epidemic curves) are seen as essential tools for understanding disease dynamics and causal factors. However, temporo-spatial visualisation has been less commonly used because of the complexity of...
PL/R function example – outbreak detection methods

PL/R function example – outbreak detection methods

Dynamic Cluster Detection using pl/r functions The ability to detect clusters of outbreaks as soon as possible was investigated. Cluster detection methods were coded as procedural language functions in the database and made available through a web interface. Methods...