On 16.02.22 14:27, Carsten Klein wrote:
> AFAIK, this conversion is done by internal function float8in, which, 
> when called directly, yields the same results:
> 
> SELECT float8in('1.56');
> 
> --> 1.55999999999999   (wrong!)   on one server, and
> --> 1.56               (correct!) on all other servers.
float8in() really just calls the operating system's strtod() function. 
I would test that one directly with a small C program.
It's also possible that different compiler options lead to different 
optimizations.