A Short Comment on Idempotence
If you’ve read the tech news in the last few weeks, chances are you’ve encountered something along the lines of “HTTP adds the QUERY method”. You can go take a look at why that’s important, but I want to stop for a second on one of the properties of this method: all articles will say that QUERY is safe and idempotent. What does this fancy-sounding word mean? In one sentence: idempotence is the property of an operation that has the same effect whether applied once or multiple times. ...