Re: How to generate a WAL record spanning multiple WAL files?

On Wed, Apr 6, 2022 at 12:41 AM Robert Haas <robertmhaas(at)gmail(dot)com> wrote:

> On Tue, Apr 5, 2022 at 10:10 AM Andy Fan <zhihui(dot)fan1213(at)gmail(dot)com> wrote:
> >> > I wanted to have a WAL record spanning multiple WAL files of size, say
> >> > 16MB. I'm wondering if the Full Page Images (FPIs) of a TOAST table
> >> > would help here. Please let me know if there's any way to generate
> >> > such large WAL records.
> >>
> >> It's easier to use pg_logical_emit_message().
> >
> > Not sure I understand the question correctly here. What if I use the
> below code
> > where the len might be very large? like 64MB.
> >
> > XLogBeginInsert();
> > XLogRegisterData((char *)&xl_append, sizeof(xl_cstore_append));
> > XLogRegisterData((char *)data, len);
> >
> > XLogInsert(..);
>
> Well, that's how to do it from C. And pg_logical_emit_message() is how
> to do it from SQL.
>
>
OK, Thanks for your confirmation!

--
Best Regards
Andy Fan