What Will this PostgreSQL Code Print? 🤔

I couldn't believe this, at first!

Here's what I get from running the query:

NOTICE: 00:00:00
DO
Total execution time: 00:00:02.072

But why will the result be 00:00:00? 🤯

This is because now() returns the start time of the current transaction, not the clock time at which the function is called. So in our case, both the first_timestamp and the second_timestamp will store exactly the same time, hence producing this zero interval!

Want to try it yourself? Check out the riddle here on the Github.