Re: Avoid unnecessary StringInfo allocation in tablesync COPY buffer

> On May 9, 2026, at 23:35, Álvaro Herrera <alvherre(at)kurilemu(dot)de> wrote:
>
> Hello,
>
> On 2026-May-09, Chao Li wrote:
>
>> I found this issue while reviewing the patch [1] and was suggested use
>> a separate thread for the issue.
>>
>> In tablesync.c, copy_table() currently does:
>> ```
>> copybuf = makeStringInfo();
>> ```
>>
>> But copybuf is only used by copy_read_data(), and there it's really
>> just acting as a small state holder for data, len, and cursor, rather
>> than as a normal growable StringInfo.
>
> I find this coding pattern weird and ugly and confusing. If what we
> need is three variables, shouldn't we have three variables instead of
> this strange misuse of the StringInfo abstraction?
>

Yep, I first considered adding a file-local structure, but decided to keep the changes minimal in the first version.

In v2, I switched to using a small file-local CopyBuf structure.

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