Re: pgbench - refactor init functions with buffers

Hi,

On 2020-03-27 19:57:12 -0400, Tom Lane wrote:
> Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr> writes:
> >>> Ok. I find it strange to mix PQExpBuffer & StringInfo in the same file.
>
> >> Agreed, but we'd rather use StringInfo going forward. However, I don't think
> >> that puts you on the hook for updating all the PQExpBuffer references.
> >> Unless you want to...
>
> > I cannot say that I "want" to fix something which already works the same
> > way, because it is against my coding principles.
> > However there may be some fun in writing a little script to replace one
> > with the other automatically. I counted nearly 3500 calls under src/bin.
>
> Yeah, that's the problem. If someone does come forward with a patch to do
> that, I think it'd be summarily rejected, at least in high-traffic code
> like pg_dump. The pain it'd cause for back-patching would outweigh the
> value.

Sure, but that's not at all what was proposed.

> That being the case, I'd think a better design principle is "make your
> new code look like the code around it", which would tend to weigh against
> introducing StringInfo uses into pgbench when there's none there now and
> a bunch of PQExpBuffer instead. So I can't help thinking the advice
> you're being given here is suspect.

I don't agree with this. This is a "fresh" usage of StringInfo. That's
different to adding one new printed line among others built with
pqexpbuffer. If we continue adding large numbers of new uses of both
pieces of infrastructure, we're just making things more confusing.

Greetings,

Andres Freund