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Re: How to generate a WAL record spanning multiple WAL files? - Mailing list pgsql-hackers

From Andy Fan
Subject Re: How to generate a WAL record spanning multiple WAL files?
Date
Msg-id CAKU4AWqsg3TuuvfrQbZqRvnyk6ZgW0S5cRue5CfRvNipSyks=A@mail.gmail.com
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In response to Re: How to generate a WAL record spanning multiple WAL files?  (Alvaro Herrera <alvherre@alvh.no-ip.org>)
Responses Re: How to generate a WAL record spanning multiple WAL files?  (Robert Haas <robertmhaas@gmail.com>)
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Hi, 

On Tue, Apr 5, 2022 at 9:46 PM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
On 2022-Apr-05, Bharath Rupireddy wrote:

> Hi,
>
> 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(..); 

--
Best Regards
Andy Fan

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