Re: random generated string matching index in inexplicable ways

[Francisco Olarte <folarte@xxxxxxxxxxxxxx>]

On Tue, May 7, 2019 at 3:12 PM Myles Miller <pg@xxxxxxxx> wrote:
> No, the function is returning just one letter, either 'A' or 'B', not multiple values.

Your random function is being evaluated ONCE FOR EACH ROW.

i.e, it's doing something like:
select y from
   ( SELECT y, chr(round(random())::int + 65) as z FROM x ) aux
WHERE y = z;
 o
with aux as ( SELECT y, chr(round(random())::int + 65) as z FROM x )
select y from aux WHERE y = z;

You may want to try something like this:

with aux as ( SELECT chr(round(random())::int + 65) as z )
select y from x,aux WHERE y = z;

( Untested, but that's the idea )

Francisco Olarte