Today I noticed that the female Aphonopelma seemanni I keep was in a death curl; it was either dying or already dead. The day before I had noticed it was leaking hemolymph from the top of its abdomen close to the pedicel. I couldn't see any damage and had no idea why this was happening.
When I inspected my other tarantulas I noticed another loss: the Caribena versicolor I keep was also in a death curl. That's two in a single day 😢.
PostgreSQL allows restoration of individual tables from dump files which can be used, for instance, to query a particular table for retrieving data from a previous state in time, say, for investigating a bug, or recovering accidentally deleted data.
Source: Restoring individual postgres table, an article by Thomas Vilhena.
Secret Santa is a traditional Christmas gift exchanging scheme in which each member of a group is randomly and anonymously assigned another member to give a Christmas gift to (usually by drawing names from a container). It is not valid for a person to be assigned to themself (if someone were to draw their own name, for example, all the names should be returned to the jar and the drawing process restarted).
Given a group of a certain size, how many different ways are there to make valid assignments? What is the probability that at least one person will draw their own name? What is the probability that two people will draw each other’s names? What is a good way to have a computer make the assignments while guaranteeing they are generated with equal probability among all possible assignments?
It turns out that these questions about secret santa present good motivation for exploring some of the fundamental concepts in combinatorics (the math of counting). In the sections below we will take a look at a bit of that math and algorithms that allow us to answer the questions we posed above. The final section presents a simple command-line program that allows generating and anonymously sending secret santa assignments via email so that we no longer need to go through the tedious ordeal of drawing names from a hat.
Source: Deranged Sinterklaas: The Math and Algorithms of Secret Santa.