Re: Performance improvements for src/port/snprintf.c - Mailing list pgsql-hackers

Andres Freund <andres@anarazel.de> writes:
> FWIW, it seems that using a local buffer and than pstrdup'ing that in
> float8out_internal is a bit faster, and would probably save a bit of
> memory on average:
> float8out using sprintf via pg_double_to_string, pstrdup:
> 15370.774
> float8out using strfromd via pg_double_to_string, pstrdup:
> 13498.331

[ scratches head ... ]  How would that work?  Seems like it necessarily
adds a strlen() call to whatever we'd be doing otherwise.  palloc isn't
going to be any faster just from asking it for slightly fewer bytes.
I think there might be something wrong with your test scenario ...
or there's more noise in the numbers than you thought.

            regards, tom lane