Re: appendPQExpBufferVA vs appendStringInfoVA

David Rowley <dgrowleyml@gmail.com> writes:
> Tom commited some changes to appendStringInfoVA a few weeks ago which
> allows it to return the required buffer size if the current buffer is not
> big enough.

> On looking at appendPQExpBufferVA I'm thinking it would be nice if it could
> make use of the new pvsnprintf function to bring the same potential
> performance improvement in to there too.

Uh ... it does contain pretty much the same algorithm now.  We can't
simply use pvsnprintf there because exit-on-error is no good for
libpq's purposes, so unless we want to rethink that, a certain
amount of code duplication is unavoidable.  But they both understand
about C99 vsnprintf semantics now.
        regards, tom lane