Every now and then there is someone on IRC, mailing lists, or private contact which asks about rules. My answer virtually always is: don't use rules. If you think that they solve your problem, think again. Why?

couple of times is was brought to attention of #postgresql channel - how to find longest prefix. case: you have phone number, and you want to find which carrier it is bound to. there are at least 3 ways of finding it, ...