Re: Making pg_rewind faster - Mailing list pgsql-hackers

Hi,

On Wed, Jul 2, 2025 at 6:40 PM Japin Li <japinli@hotmail.com> wrote:
>
> >
>
> Splitting the logs from $PGDATA is definitely better. The question is whether
> it's worth implementing this directly in core or if a prominent note in the
> documentation would suffice.
>

I can work on the documentation update as a separate patch if folks
think this is worthwhile.

> >> On Wed, Jul 2, 2025 at 10:21 AM Japin Li <japinli@hotmail.com> wrote:
>
> Exactly!  It's confusing that getFileType() returns file_content_type_t
> instead of file_type_t.
>

Ah yes that is confusing, updated in patch.

> For v5 patch:
>
> 1.
> We could simply use the global WalSegSz variable within decide_file_action(),
> eliminating the need to pass wal_segsz_bytes as an argument.
>

Good point.

> 2.
> For last_common_segno, we could implement it similarly to WalSegSz, avoiding a
> signature change for decide_file_actions() and decide_file_action().  I'm not
> insisting on this approach, however.
>

I made it a global as well, and had to include access/xlog_internal.h
in pg_rewind.h but I don't feel strongly about it either way.

Thanks,

--
John Hsu - Amazon Web Services