Comment by roessland

The default PG type, `numeric`, has almost arbitary precision.

    select pg_typeof(9999999999999999.0); 
    -- numeric

    select 9999999999999999.0::double precision 
           - 9999999999999998.0::double precision; 
    -- 2

More interesting perhaps, is mixing up `real` (aka float32) with `numeric`:

    select 9999999999999999.0::real - 9999999999999998.0;
    -- 272564226 (?! can anyone explain?)

    select 9999999999999999.0::real;
    -- 10000000300000000

Wat