Re: Make COPY format extendable: Extract COPY TO format implementations

> On Jul 25, 2024, at 12:51, Sutou Kouhei <kou(at)clear-code(dot)com> wrote:
>
> Hi,
>
> THREAD SUMMARY:

Very nice summary.

>
> Implementation:
>
> The v18 patch set is the latest patch set. [6]
> It includes the following patches:
>
> 0001: This adds a basic feature (Copy{From,To}Routine)
> (This isn't enough for extending COPY format.
> This just extracts minimal procedure sets to be
> extendable as callback sets.)
> 0002: This uses Copy{From,To}Rountine for the existing
> formats (text, csv and binary)
> (This may not be committed because there is a
> profiling related concern. See the following section
> for details)
> 0003: This adds support for specifying custom format by
> "COPY ... WITH (format 'my-format')"
> (This also adds a test for this feature.)
> 0004: This exports Copy{From,To}StateData
> (But this isn't enough to implement custom COPY
> FROM/TO handlers as an extension.)
> 0005: This adds opaque member to Copy{From,To}StateData and
> export some functions to read the next data and flush
> the buffer
> (We can implement a PoC Apache Arrow COPY FROM/TO
> handler as an extension with this. [7])
>
> Thanks,
> --
> kou
>

This review is for 0001 only because the other patches are not ready
for commit.

The v18-0001 patch applies cleanly to HEAD. “make check-world” also
runs cleanly. The patch looks good for me.

Regards,
Yong