# Friday Blast #3

A shorter blast this week, on account of being on vacation.

A brief history of the UUID (2017) - what I expected to be a short article about UUIDs turned into a deep dive into their long history. There’s even some code archeology involved. Fun fact: telephone numbers were the first unique identifiers we used in communication.

The best icon is a text label (2015) - and the best summary is the title itself.

Implementing state machines in PostgreSQL (2017) - worth it alone for the advanced usage of Postgres, this article talks about various ways of implementing state machines directly in Postgres. More than just having a `state`

column and letting application code deal with state management, that is.

Boolean logic in polynomials (2017) - a neat way to encode boolean formulas as polynomials. You transform a boolean expression \(A\) with variables \(x_1, x_2, \dots, x_n\) into a polynomial \(A_P\) in \(x_1, x_2, \dots, x_n\) by turning every `AND`

into multiplication and every negation of a term \(F\) into \(1 - F_P\). `OR`

is handled by DeMorgan’s law. There’s two or three examples in the article of real-life[1] applications of this transformation as well.

[1] Real-life CS theory at least.