Generate random String in PostgreSQL

Question

I'm using this SQL query to generate random value in PostgreSQL

chr(ascii('B') + (random() * 25)::integer)

How I can generate 15 characters random String using the same query?

Answer 1

Another solution that's pretty easy to read (perf should be reasonable, but no benchmarks were performed):

select substr(md5(random()::text), 0, 25);

Could be uppercased if you prefer:

select upper(substr(md5(random()::text), 0, 25));