Re: Avoid repeated scans of the output buffer in oidvectortypes()

> On Oct 15, 2026, at 18:43, David Rowley <dgrowleyml(at)gmail(dot)com> wrote:
>
> On Thu, 15 Oct 2026 at 23:20, Japin Li <japinli(at)hotmail(dot)com> wrote:
>> I believe the current patch is the smallest correct fix. Introducing StringInfo
>> would be unnecessary over-engineering.
>
> I'm assuming this is master only, so why does it need to be a minimal
> fix? StringInfo is just the way we normally do incremental building of
> strings. It's an API that most people who work on our code understand.
> Manually calling repalloc() is tedious and more likely to have bugs.
>
> Using StringInfo will also cut down on the number of reallocs due to
> the size doubling. It'll also allow the
> PG_RETURN_TEXT_P(cstring_to_text(result)); to be updated to use
> cstring_to_text_with_len using the StringInfo's len field.
>
> David

I tried StringInfo first. A few minor reasons led me to choose the v1 approach:

* v1 made fewer changes to the existing code.
* v1 was slightly faster in my test. With debug and assertions disabled, v1 took about 20 ms and StringInfo about 24 ms, averaged over multiple runs.

I agree that using the usual API outweigh these minor considerations. I've updated the patch to use StringInfo in v2.

Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/