How to add “weights” to a MySQL table and select random values according to these?

Question

I want to create a table, with each row containing some sort of weight. Then I want to select random values with the probability equal to (weight of that row)/(weight of all

Answer 1

The problem is called Reservoir Sampling (https://en.wikipedia.org/wiki/Reservoir_sampling)

The A-Res algorithm is easy to implement in SQL:

SELECT *
FROM table
ORDER BY pow(rand(), 1 / weight) DESC
LIMIT 10;